JP6460388B2 - Magnetoresistive device - Google Patents

Description

  The present invention relates to a magnetoresistive device.

  In recent years, research on products that apply spintronics-specific phenomena has been promoted, and one of the phenomena that has attracted attention is due to magnetoresistive effect elements that have a magnetization fixed layer and a magnetization free layer via a spacer layer. Spin torque oscillation. By applying a magnetic field by a magnetic field application mechanism at the same time as applying a direct current to the magnetoresistive effect element having this structure, spin torque oscillation can be generated in the magnetoresistive effect element. An alternating current is output from the magnetoresistive element. During this spin torque oscillation, the spin torque resonance frequency of the magnetoresistive element increases as the magnetic field applied to the magnetoresistive element increases. Further, at the time of spin torque oscillation, the spin torque resonance frequency of the magnetoresistive element decreases as the current density of the direct current flowing to the magnetoresistive element increases. When the spacer layer is equipped with magnetic nanocontacts, when a direct current is passed through the magnetoresistive effect element, a spin-polarized current flows in the magnetic nanocontact, and the spins in the magnetic nanocontact start precession, Spin torque oscillation occurs. At this time, the higher the current density of the direct current flowing in the magnetic nanocontact, the higher the spin torque resonance frequency in the magnetic nanocontact of the magnetoresistive element.

  A magnetoresistive effect device such as an oscillator using spin torque oscillation by a magnetoresistive effect element is currently being studied. As one of methods for increasing the output of the magnetoresistive effect element, the prior art document 1 describes a magnetoresistive effect element. Integration in series and parallel connection is shown. By simultaneously applying a magnetic field and a direct current to all the integrated magnetoresistive effect elements and oscillating at the same spin torque resonance frequency, high power oscillation can be obtained from the integrated magnetoresistive effect elements.

Patent No. 5495108

  However, when a magnetic field is applied to an integrated magnetoresistive effect element using a magnetic field application mechanism, the magnetic field strength applied to each element due to the structure of the magnetic field application mechanism, etc., or due to differences in the structure of each element If the variation of the spin torque resonance frequency of each element increases due to the variation of the spin torque resonance frequency between the elements, the problem is that the oscillation output from the integrated magnetoresistive effect element decreases. The present invention has been made to solve such a problem, and an object thereof is to provide a magnetoresistive effect device capable of obtaining a large oscillation output.

  The magnetoresistive effect device of the present invention includes a spacer layer made of a single material, a magnetoresistive effect element including a magnetization fixed layer and a magnetization free layer via the spacer layer, and a magnetic field applied to the magnetoresistive effect element. A plurality of series element portions including the magnetoresistive effect element connected in parallel, and the magnetic field applied to each magnetoresistive effect element is the same as each magnetoresistive effect element. The magnitude relationship between the spin torque resonance frequencies of the magnetoresistive effect elements when a direct current having a large current density is passed is the same as the magnitude relationship between the current densities of the DC currents actually flowing through the magnetoresistive effect elements. It is characterized by being.

  Here, the spins of the magnetoresistive effect elements of the part A and the part B when a direct current of the same current density J0 is passed through each magnetoresistive effect element included in any two series element parts (part A, part B). The torque resonance frequencies are assumed to be fa0 and fb0, respectively, and the current densities of the direct currents actually flowing through the magnetoresistive effect elements in the parts A and B are assumed to be Ja and Jb, respectively. When direct currents having the same current density J0 flow through the magnetoresistive effect elements in the portions A and B, Ja = Jb. In the case of fa0> fb0, by setting Ja> Jb, when the current density of the direct current flowing through the magnetoresistive effect element of the portion A is J0, the current density Jb of the direct current flowing through the magnetoresistive effect element of the portion B is Jb <J0. Accordingly, since the spin torque resonance frequency of the magnetoresistive effect element in the portion B at this time is higher than fb0, the difference from fa0 can be reduced. Further, in the case of fa0 <fb0, by setting Ja <Jb, when the current density of the direct current flowing through the magnetoresistive effect element of the portion A is J0, the current density of the direct current flowing through the magnetoresistive effect element of the portion B Jb is Jb> J0. Therefore, since the spin torque resonance frequency of the magnetoresistive effect element in the portion B at this time is lower than fb0, the difference from fa0 can be reduced. Therefore, according to the magnetoresistive effect device having this feature, it is possible to suppress variation in the frequency of the output current and obtain a large oscillation output.

  Furthermore, the magnetoresistance effect device of the present invention is characterized in that at least one of the series element portions includes a resistance element connected in series with the magnetoresistance effect element.

  According to this, since the resistance value of each series element portion can be adjusted by the resistance element, the adjustment of the spin torque resonance frequency of the magnetoresistive effect element by the resistance value becomes easier.

  Further, each of the magnetoresistive elements has the same film structure. The “same film structure” in the present invention means that the materials and film thicknesses of the layers constituting the magnetoresistive element are the same, and the stacking order of the layers is the same.

  According to this, since all the magnetoresistive effect elements can be formed into a thin film on one wafer at a time, manufacturing becomes easier.

  The magnetoresistive effect device of the present invention includes a spacer layer provided with magnetic nanocontacts, a magnetoresistive effect element provided with a magnetization fixed layer and a magnetization free layer via the spacer layer, and a magnetic field applied to the magnetoresistive effect element. A plurality of series element portions including the magnetoresistive effect element connected in parallel, and the magnetic field applied to the magnetoresistive effect element in the state where the magnetic field is applied to the magnetoresistive effect element. The magnitude relationship of the spin torque resonance frequency of each magnetoresistive effect element when a direct current having the same current density is passed through the magnetic nanocontact, and the direct current that actually flows through the magnetic nanocontact of each magnetoresistive effect element It is characterized in that the magnitude relation of the current density of the current is opposite.

  Here, the magnetoresistance of the part A and the part B when a direct current of the same current density J0 is applied to the magnetic nanocontacts of each magnetoresistive effect element included in any two series element parts (part A, part B). It is assumed that the spin torque resonance frequencies of the effect element are fa0 and fb0, respectively, and the current densities of the direct currents that actually flow through the magnetic nanocontacts of the magnetoresistive effect element included in the part A and the part B are Ja and Jb, respectively. When a direct current of the same current density J0 flows through the magnetic nanocontacts of the magnetoresistive effect elements of the part A and the part B, Ja = Jb. In the case of fa0> fb0, by setting Ja <Jb, when the current density of the direct current flowing through the magnetic nanocontact of the magnetoresistive effect element of the portion A is J0, the magnetic nanocontact of the magnetoresistive effect element of the portion B is The current density Jb of the flowing direct current is Jb> J0. Accordingly, since the spin torque resonance frequency of the magnetoresistive effect element in the portion B at this time is higher than fb0, the difference from fa0 can be reduced. Further, in the case of fa0 <fb0, by setting Ja> Jb, when the current density of the direct current flowing through the magnetic nanocontact of the magnetoresistive effect element of the portion A is J0, the magnetic nanometer of the magnetoresistive effect element of the portion B is The current density Jb of the direct current flowing through the contact is Jb <J0. Therefore, since the spin torque resonance frequency of the magnetoresistive effect element in the portion B at this time is lower than fb0, the difference from fa0 can be reduced. Therefore, according to the magnetoresistive effect device having this feature, it is possible to suppress variation in the frequency of the output current and obtain a large oscillation output.

  Furthermore, the magnetoresistance effect device of the present invention is characterized in that at least one of the series element portions includes a resistance element connected in series with the magnetoresistance effect element.

  According to this, since the current density of the direct current flowing through each series element portion can be adjusted by adjusting the resistance value of each series element portion by the resistance element, the magnetoresistive effect element by adjusting the current density can be adjusted. Adjustment of the spin torque resonance frequency becomes easier.

  Further, each of the magnetoresistive elements has the same film structure.

  According to this, since all the magnetoresistive effect elements can be formed into a thin film collectively on a single wafer, the manufacturing becomes easier.

  According to the present invention, it is possible to provide a magnetoresistive effect device capable of obtaining a large oscillation output.

It is sectional drawing of the magnetoresistive effect device of Embodiment 1 of this invention. It is a figure which shows the relationship between the current density J of the direct current which flows into the magnetoresistive element in Embodiment 1 of this invention, and the spin torque resonance frequency f. It is a figure which shows the relationship between the oscillation output from the magnetoresistive effect device in Embodiment 1 of this invention, and a frequency. It is a figure which shows the relationship between the oscillation output from the magnetoresistive effect device in Embodiment 1 of this invention, and a frequency. It is a figure which shows the relationship between the oscillation output from the magnetoresistive effect device in Embodiment 1 of this invention, and a frequency. It is a figure which shows the relationship between the oscillation output from the magnetoresistive effect device in Embodiment 1 of this invention, and a frequency. It is sectional drawing of the magnetoresistive effect device of Embodiment 2 of this invention. It is a top view of the magnetoresistive effect device of Embodiment 2 of the present invention. It is a figure which shows the relationship between the current density J of the direct current which flows into the magnetoresistive element in Embodiment 2 of this invention, and the spin torque resonance frequency f. It is a figure which shows the relationship between the oscillation output from the magnetoresistive effect device in Embodiment 2 of this invention, and a frequency. It is a figure which shows the relationship between the oscillation output from the magnetoresistive effect device in Embodiment 2 of this invention, and a frequency. It is a figure which shows the relationship between the oscillation output from the magnetoresistive effect device in Embodiment 2 of this invention, and a frequency. It is a figure which shows the relationship between the oscillation output from the magnetoresistive effect device in Embodiment 2 of this invention, and a frequency. It is sectional drawing of the magnetoresistive effect device of Embodiment 3 of this invention. It is a figure which shows the relationship between the current density J of the direct current which flows into the magnetoresistive element in Embodiment 3 of this invention, and the spin torque resonance frequency f. It is a figure which shows the relationship between the oscillation output from the magnetoresistive effect device in Embodiment 3 of this invention, and a frequency. It is a figure which shows the relationship between the oscillation output from the magnetoresistive effect device in Embodiment 3 of this invention, and a frequency. It is a figure which shows the relationship between the oscillation output from the magnetoresistive effect device in Embodiment 3 of this invention, and a frequency. It is a figure which shows the relationship between the oscillation output from the magnetoresistive effect device in Embodiment 3 of this invention, and a frequency.

  Hereinafter, preferred embodiments of the present invention will be described. However, the present invention is not limited to these embodiments, and is included in the scope of the present invention as long as the form has the technical idea of the present invention. Each configuration in each embodiment, a combination thereof, and the like are examples, and the addition, omission, replacement, and other changes of the configuration can be made without departing from the spirit of the present invention. Further, the present invention is not limited by the embodiments, and is limited only by the scope of the claims.

(Embodiment 1)
FIG. 1 is a cross-sectional view of a magnetoresistive effect device 100 according to Embodiment 1 of the present invention. The magnetoresistive effect device 100 according to the first exemplary embodiment includes a plurality of series element portions 101 including a magnetoresistive effect element 102 and a resistance element 103, and a magnetic field application mechanism 107. The magnetoresistive element 102 includes a spacer layer 105 made of a single material and a magnetization fixed layer 104 and a magnetization free layer 106 via the spacer layer 105. More specifically, the magnetoresistive effect device 100 includes three series element portions 101a, 101b, and 101c. The series element portion 101a includes a magnetoresistive effect element 102a and a resistor element 103a, and the series element portion 101b includes a magnetoresistive element. The effect element 102b and the resistance element 103b are included, and the series element portion 101c includes the magnetoresistance effect element 102c and the resistance element 103c. The magnetoresistive elements 102a, 102b, and 102c have the same configuration (the same film structure, shape, and size).

  The serial element portions 101a, 101b, and 101c are stacked on the semiconductor substrate 113, and the insulator layer 110 is disposed outside the serial element portions 101a, 101b, and 101c.

  The magnetoresistive effect element 102 (102a, 102b, 102c) has a function of converting an input direct current into an alternating current by spin torque oscillation in the magnetoresistive effect device 100.

  The spin torque oscillation of the magnetoresistive effect element 102 will be described. Oscillation is a phenomenon in which electrical vibration is induced by a non-vibrating direct current.

  The oscillation of the magnetoresistive effect element 102 is caused by the magnetization dynamics of the magnetic layer of the magnetoresistive effect element 102. At the same time as applying the magnetic field by the magnetic field applying mechanism 107, a direct current in the direction of the magnetization fixed layer 104 is applied from the magnetization free layer 106 through the spacer layer 105 in the direction perpendicular to the laminated surface of the magnetoresistive effect element 102. Due to the precession of the magnetization of the magnetization free layer 106 generated in step (b), a magnetoresistance effect in which the resistance value changes at a high frequency is generated, and an alternating current that vibrates at a high frequency of about 100 MHz to several tens of THz is generated. The magnetoresistive effect elements 102a, 102b, and 102c all have a circular shape when viewed from the plane parallel to the film surface.

  Next, the magnetization fixed layer 104, the spacer layer 105, and the magnetization free layer 106 will be described.

  The magnetization fixed layer 104 has a function in which the magnetization direction is not changed by a magnetic field generated from the magnetic field application mechanism 107. The magnetization fixed layer 104 is preferably made of a high spin polarizability material such as Fe, Co, Ni, FeCo, or CoFeB. Thereby, high output spin torque oscillation can be obtained. Although not shown, an antiferromagnetic layer made of a material such as PtMn, FeMn, or IrMn may be added so as to be in contact with the magnetization fixed layer 104 in order to fix the magnetization of the magnetization fixed layer 104. As a result, the fixed strength in the magnetization direction of the magnetization fixed layer 104 can be increased. Further, the magnetization may be fixed using magnetic anisotropy caused by the crystal structure, shape, etc. of the magnetization fixed layer 104.

The spacer layer 105 has a function of obtaining a magnetoresistance effect by causing the magnetization of the magnetization fixed layer 104 and the magnetization of the magnetization free layer 106 to interact with each other. The spacer layer 105 is made of a single material and may be made of a nonmagnetic conductive material such as Cu or Ag, or a nonmagnetic material such as AlOx (aluminum oxide), MgO (magnesium oxide), or MgAl ₂ O _4. It may be made of an insulating material. The spacer layer 105 may be made of a magnetic material.

  The magnetization free layer 106 has a function of changing the magnetization direction by a magnetic field generated from the magnetic field application mechanism 107. The magnetization free layer 106 is preferably made of a high spin polarizability material such as Fe, Co, Ni, FeCo, or CoFeB. Thereby, high output spin torque oscillation can be obtained.

  As shown in FIG. 1, the resistance elements 103a, 103b, and 103c are connected in series to the magnetoresistance effect elements 102a, 102b, and 102c, respectively, and adjust the resistance values of the serial element portions 101a, 101b, and 101c. The resistance elements 103a, 103b, and 103c may be made of a conductive material such as Cu, Ag, or NiCr, or may be made of a semiconductor such as Si or Ge.

  The magnetic field application mechanism 107 applies a magnetic field to the magnetoresistive effect element 102. By applying a direct current to the magnetoresistive effect element 102 with a magnetic field applied to the magnetoresistive effect element 102, spin torque oscillation occurs, and an alternating current having the same frequency as the spin torque resonance frequency is output from the magnetoresistive effect element 102. Is done. The magnetic field application mechanism 107 of this embodiment is a single permanent magnet, and is arranged on the magnetoresistive element 102c side as shown in FIG. The magnetic field application mechanism 107 is not limited to a single permanent magnet, but may be a plurality of permanent magnets, electromagnets, or loop coils.

  As shown in FIG. 1, a signal electrode layer 108 and a ground electrode layer 109 are disposed in the stacking direction of the magnetoresistive effect element 102 via a series element portion 101. A DC current input terminal 111 and an AC current output terminal 112 are connected to the signal electrode layer 108. Further, the series element portions 101a, 101b, and 101c are electrically connected in parallel between the signal electrode layer 108 and the ground electrode layer 109, and the DC current input terminal 111 is connected to a DC voltage source or a DC current source, and grounded. When the electrode layer 109 is connected to the ground of the DC voltage source or the DC current source, a DC current is simultaneously applied to the series element portions 101a, 101b, and 101c, and a magnetic field is applied by the magnetic field applying mechanism 107, thereby the magnetoresistive effect element. An alternating current is taken out from the alternating current output terminal 112 by causing the spin torque oscillation in 102a, 102b, and 102c. Here, in each of the serial element portions 101a, 101b, and 101c, a plurality of resistance elements 103a, 103b, and 103c may be connected between the signal electrode layer 108 and the ground electrode layer 109.

  The resistance values of the resistance elements 103a, 103b, and 103c are Ra, Rb, and Rc. In the magnetoresistance effect device 100, Rc <Rb <Ra. For example, as a material of the resistance elements 103a, 103b, and 103c, a semiconductor containing an impurity is used, and the resistance values of the resistance elements 103a, 103b, and 103c are changed by changing the impurity contents in the resistance elements 103a, 103b, and 103c. Can be different. The magnetoresistive elements 102a, 102b, and 102c have the same film structure and are connected in parallel. Therefore, if Ra = Rb = Rc, the same as the magnetoresistive elements 102a, 102b, and 102c. A current having a large current density flows. In the magnetoresistive effect device 100, since Rc <Rb <Ra, assuming that the current densities of the direct currents actually flowing through the magnetoresistive effect elements 102a, 102b, 102c are Ja, Jb, Jc, respectively, Ja <Jb <Jc.

  The strength of the magnetic field generated by the magnetic field applying mechanism 107 is inversely proportional to the distance from the magnetic field applying mechanism 107, and the magnetic field strength of the place where the magnetoresistive effect element 102a is arranged is Ha and the magnetoresistive effect element 102b is arranged. If the magnetic field strength at the place where the magnetic resistance effect element 102c is located is Hb and the magnetic field strength at the place where the magnetoresistive effect element 102c is arranged is Hc, then Ha <Hb <Hc. That is, in the magnetoresistive effect device 100, the magnitude relationship (Ha <Hb <Hc) of the magnetic field strengths Ha, Hb, Hc applied to the magnetoresistive effect elements 102a, 102b, 102c, and the magnetoresistive effect elements 102a, The magnitude relations (Rc <Rb <Ra) of the resistance values Ra, Rb, Rc of the resistance elements 103a, 103b, 103c of the series element portions 101a, 101b, 101c corresponding to 102b, 102c are opposite to each other. The magnitude relationship (Ha <Hb <Hc) of the magnetic field strengths Ha, Hb, Hc applied to the resistance effect elements 102a, 102b, 102c, and the current of the direct current that actually flows through each of the magnetoresistance effect elements 102a, 102b, 102c. The magnitude relationships (Ja <Jb <Jc) of the densities Ja, Jb, and Jc are the same. Here, the spin torque oscillation frequencies of the magnetoresistive effect elements 102a, 102b, and 102c when a direct current of the same current density J0 flows through the magnetoresistive effect elements 102a, 102b, and 102c are fa0, fb0, and fc0, respectively. Then, as the magnetic field applied to the magnetoresistive element increases, the spin torque resonance frequency of the magnetoresistive element increases, so that fa0 <fb0 <fc0.

  FIG. 2 shows the relationship between the current density J of the direct current flowing through the magnetoresistive elements 102a, 102b, and 102c and the spin torque resonance frequency f. A straight line A in FIG. 2 represents the relationship between the current density J of the direct current flowing through the magnetoresistive effect element 102a and the spin torque resonance frequency fa of the magnetoresistive effect element 102a. A straight line B in FIG. 2 shows the relationship between the current density J of the direct current flowing through the magnetoresistive effect element 102b and the spin torque resonance frequency fb of the magnetoresistive effect element 102b. A straight line C in FIG. 2 shows the relationship between the current density J of the direct current flowing through the magnetoresistive effect element 102c and the spin torque resonance frequency fc of the magnetoresistive effect element 102c. As shown in FIG. 2, in a magnetoresistive element having a spacer layer made of a single material, the spin torque resonance frequency of the magnetoresistive element decreases as the current density of the direct current flowing through the magnetoresistive element increases. .

  3A, 3B, 3C, and 3D show the frequency distribution of the oscillation output from the magnetoresistive effect device 100. FIG. FIG. 3A shows a magnetoresistive effect device 100 when the resistance values of the resistance elements 103a, 103b, and 103c are Ra = Rb = Rc and the current density of the direct current flowing through the magnetoresistive effect elements 102a, 102b, and 102c is J0. It is a frequency distribution of the oscillation output from. At this time, as shown in FIG. 3A, a high output cannot be obtained due to variations in the frequency of the output current.

  First, when the resistance value Ra of the resistance element 103a included in the series element portion 101a is larger than the resistance value Rb of the resistance element 103b included in the series element portion 101b, the current of the direct current flowing through the magnetoresistive effect element 102b. When the density is J0, the current density of the direct current Ja flowing through the magnetoresistive element 102a is smaller than J0 (= Jb), and as shown in FIG. 3B, fa can be made closer to fb (= fb0). Similarly, when the resistance value Rc of the resistance element 103c included in the series element portion 101c is smaller than the resistance value Rb of the resistance element 103b included in the series element portion 101b, the direct current flowing through the magnetoresistive effect element 102b When the current density of J0 is J0, the current density Jc of the direct current flowing through the magnetoresistive effect element 102c becomes larger than J0 (= Jb), and as shown in FIG. 3C, fc may approach fb (= fb0). it can. Therefore, a direct current J0 having the same current density is supplied to each magnetoresistive effect element 102a, 102b, 102c in a state where the magnetic field applied by the magnetic field applying mechanism 107 is applied to each magnetoresistive effect element 102a, 102b, 102c. And the magnitude relationship (fa0 <fb0 <fc0) of the spin torque oscillation frequencies fa0, fb0, fc0 of the magnetoresistive effect elements 102a, 102b, 102c and the direct current that actually flows through the magnetoresistive effect elements 102a, 102b, 102c. Since the magnitude relationships of the current densities Ja, Jb, and Jc are the same, that is, Ja <Jb <Jc, the oscillation output from the magnetoresistive effect device 100 can be increased as shown in FIG. 3D. Become. Here, the resistance value Ra of the resistance element 103a is Ja≈J1 as shown in FIG. 2, and the resistance value Rc of the resistance element 103c is Jc≈J2 as shown in FIG. It is desirable to be determined. As described above, according to the magnetoresistive effect device 100, the variation in the frequency of the output current due to the variation in the strength of the magnetic field applied by the magnetic field application mechanism 107 is suppressed, and a large oscillation output can be obtained.

  In the magnetoresistive effect device 100, since the serial element portions 101a, 101b, and 101c include the resistive elements 103a, 103b, and 103c connected in series with the magnetoresistive effect elements 102a, 102b, and 102c, the resistive elements 103a, 103b, Since the resistance value of each of the serial element portions 101a, 101b, and 101c can be adjusted by 103c, the adjustment of the spin torque resonance frequency of the magnetoresistive effect elements 102a, 102b, and 102c by the resistance value is simple.

  Furthermore, since each magnetoresistive effect element 102a, 102b, 102c has the same film structure, all the magnetoresistive effect elements 102a, 102b, 102c can be formed into a thin film at once on one wafer. The magnetoresistive device 100 is easy to manufacture.

  In the first embodiment, the resistance elements 103a, 103b, and 103c are included in the series element portions 101a, 101b, and 101c, respectively, but the resistance elements 103a, 103b, and 103c are not necessarily included in the series element portions 101a, 101b, and 101c. It does not have to be. For example, the serial element portion 101c may be configured by only the magnetoresistive element 102c. In this case, although the resistance element is not included in the series element portion 101c, the resistance value of the resistance element of the series element portion 101c is regarded as the minimum, and the magnitude relation of the resistance value of the resistance element of each series element portion is considered.

  In the first embodiment, the magnetoresistive elements 102a, 102b, and 102c have the same film structure, but the magnetoresistive elements 102a, 102b, and 102c do not have to have the same film structure. For example, the resistance values of the magnetoresistive elements 102a, 102b, and 102c are made different by changing the thickness of the spacer layer 105 between the magnetoresistive elements 102a, 102b, and 102c, so that the resistive elements 103a, 103b, and 103c are changed. The magnitude relationship between the current densities Ja, Jb, and Jc of the direct currents that actually flow through the magnetoresistive elements 102a, 102b, and 102c may be adjusted without using.

  In the first embodiment, the magnetoresistive elements 102a, 102b, and 102c have the same cross-sectional area perpendicular to the current direction, but may have different cross-sectional areas perpendicular to the current direction. For example, the magnetoresistive elements 102a, 102b, and 102c have the same film structure, the cross-sectional shape perpendicular to the current direction is similar (the aspect ratio of the cross-sectional shape is the same), and the cross-section perpendicular to the current direction is the same. The cross-sectional areas may be different. In this case, when only the magnetoresistance effect elements 102a, 102b, and 102c are connected in parallel without using the resistance elements 103a, 103b, and 103c, currents of the same magnitude are supplied to the magnetoresistance effect elements 102a, 102b, and 102c. Since the direct current of the density flows, the current density Ja, Jb, Jc of the direct current that actually flows through the magnetoresistive elements 102a, 102b, 102c using the resistance elements 103a, 103b, 103c as in the first embodiment. Can be adjusted. Here, the aspect ratio is the ratio of the major axis length to the minor axis length (major axis length / minor axis length) when the cross-sectional shape or planar view shape is an ellipse. Yes, in the case of a rectangle, the ratio of the length of the long side to the length of the short side (long side length / short side length). The aspect ratio is 1 when the cross-sectional shape or planar view shape is circular or square.

(Embodiment 2)
FIG. 4 is a cross-sectional view of a magnetoresistive effect device 400 according to Embodiment 2 of the present invention. In the magnetoresistive effect device 400, the description common to the magnetoresistive effect device 100 of Embodiment 1 is omitted as appropriate. Elements common to the magnetoresistive effect device 100 of Embodiment 1 are denoted by the same reference numerals, and description of common elements is omitted. The magnetoresistive effect device 400 according to the second embodiment includes serial element portions 401a, 401b, and 401c instead of the serial element portions 101a, 101b, and 101c in the magnetoresistive effect device 100 according to the first embodiment, and includes the magnetoresistive effect element 102a. , 102b, and 102c, magnetoresistive effect elements 402a, 402b, and 402c are provided. Resistive elements 103a, 103b, and 103c are provided, and resistive elements 403a, 403b, and 403c are provided. A mechanism 407 is included. The magnetoresistive effect device 400 includes a plurality of series element portions 401 including a magnetoresistive effect element 402 and a resistive element 403, and a magnetic field application mechanism 407. The magnetoresistive element 402 includes a spacer layer 105 made of a single material and a magnetization fixed layer 104 and a magnetization free layer 106 via the spacer layer 105. More specifically, the magnetoresistive effect device 500 includes three series element portions 401a, 401b, and 401c. The series element portion 401a includes a magnetoresistive effect element 402a and a resistor element 403a, and the series element portion 401b is a magnetoresistive element. The series element portion 401c includes a magnetoresistive effect element 402c and a resistance element 403c.

  The magnetic field application mechanism 407 is composed of two permanent magnets, and the two permanent magnets are arranged so as to sandwich both sides of the magnetoresistive effect elements 402a, 402b, and 402c as shown in FIG. Instead of the permanent magnet of the magnetic field application mechanism 407, an electromagnet or a loop coil may be used. In this case, the strengths of the magnetic fields applied from the magnetic field application mechanism 407 to the magnetoresistive elements 402a, 402b, and 402c are equal to each other.

  The film structure of the magnetoresistive effect elements 402a, 402b, and 402c is the same as that of the magnetoresistive effect elements 102a, 102b, and 102c of the first embodiment. The magnetoresistive elements 402a, 402b, and 402c have a rectangular shape in plan view of a plane parallel to the film surface, but have different aspect ratios. FIG. 5 is a top view of the magnetoresistive effect device 400. The magnetic field strength of the magnetic field applied to the magnetoresistive effect elements 402a, 402b, and 402c by the magnetic field applying mechanism 407 is the same, and the long side of the plane view shape parallel to the film surface of the magnetoresistive effect elements 402a, 402b, and 402c A magnetic field in substantially the same direction as the direction is applied to the magnetoresistive effect elements 402a, 402b, and 402c. As shown in FIG. 5, the dimension in the Y direction of the planar view shape of the plane parallel to the film surface of the magnetoresistive effect elements 402a, 402b, and 402c is the same, but the dimension in the X direction that is the long side direction is different. Yes. Here, when the dimension in the Y direction of the magnetoresistive effect elements 402a, 402b, and 402c is Y0, and the dimension in the X direction of the magnetoresistive effect elements 402a, 402b, and 402c is Xa, Xb, and Xc, respectively, the aspect ratio (X / Y ) Is (Xa / Y0) <(Xb / Y0) <(Xc / Y0). In this case, the spin torque resonance frequencies of the magnetoresistive elements 402a, 402b, and 402c when a direct current of the same current density J0 is passed through the magnetoresistive elements 402a, 402b, and 402c are fa0, fb0, Assuming fc0, the spin torque resonance frequency of the magnetoresistive element increases as the aspect ratio of the planar shape of the plane parallel to the film surface of the magnetoresistive element increases, so that fa0 <fb0 <fc0.

  The resistance values of the resistance elements 403a, 403b, and 403c are Ra, Rb, and Rc. In the magnetoresistance effect device 400, Rc <Rb <Ra. Since the magnetoresistive elements 402a, 402b, and 402c have the same film structure and are connected in parallel, if Ra = Rb = Rc, it is the same as the magnetoresistive elements 402a, 402b, and 402c. A current having a large current density flows. In the magnetoresistive effect device 400, since Rc <Rb <Ra, if the current densities of the direct currents actually flowing through the magnetoresistive effect elements 402a, 402b, and 402c are Ja, Jb, and Jc, respectively, Ja <Jb <Jc.

  In the magnetoresistive effect device 400, the aspect ratios (Xa / Y0), (Xb / Y0), and (Xc / Y0) of the planar view shape of the plane parallel to the film surface of each of the magnetoresistive elements 402a, 402b, and 402c are large or small. The relationship ((Xa / Y0) <(Xb / Y0) <(Xc / Y0)) and the resistance elements 403a, 403b of the series element portions 401a, 401b, 401c corresponding to the magnetoresistive elements 402a, 402b, 402c , 403c resistance values Ra, Rb, Rc are opposite in magnitude (Rc <Rb <Ra), and the aspect of the planar view of the plane parallel to the film surface of each of the magnetoresistive elements 402a, 402b, 402c The magnitude relationship ((Xa / Y0) <(Xb / Y0) <(Xc / Y0)) of the ratios (Xa / Y0), (Xb / Y0), and (Xc / Y0)) and the magnetoresistive elements 40 actually a, 402b, current density Ja of the DC current flowing through 402c, Jb, the magnitude relation of Jc (Ja <Jb <Jc) is the same.

  FIG. 6 shows the relationship between the current density J of the direct current flowing through the magnetoresistive elements 402a, 402b, and 402c and the spin torque resonance frequency f. A straight line A in FIG. 6 represents the relationship between the current density J of the direct current flowing through the magnetoresistive effect element 402a and the spin torque resonance frequency fa of the magnetoresistive effect element 402a. A straight line B in FIG. 6 shows the relationship between the current density J of the direct current flowing through the magnetoresistive effect element 402b and the spin torque resonance frequency fb of the magnetoresistive effect element 402b. A straight line C in FIG. 6 shows the relationship between the current density J of the direct current flowing through the magnetoresistive effect element 402c and the spin torque resonance frequency fc of the magnetoresistive effect element 402c. As shown in FIG. 6, in a magnetoresistive element having a spacer layer made of a single material, the spin torque resonance frequency of the magnetoresistive element decreases as the current density of the direct current flowing through the magnetoresistive element increases. .

  7A, 7B, 7C, and 7D show the frequency distribution of the oscillation output from the magnetoresistive effect device 400. FIG. FIG. 7A shows a magnetoresistive effect device 400 in which the resistance values of the resistance elements 403a, 403b, and 403c are Ra = Rb = Rc and the current density of the direct current flowing through the magnetoresistive effect elements 402a, 402b, and 402c is J0. It is a frequency distribution of the oscillation output from. At this time, as shown in FIG. 7A, a high output cannot be obtained due to variations in the frequency of the output current.

  First, when the resistance value Ra of the resistance element 403a included in the series element portion 401a is larger than the resistance value Rb of the resistance element 403b included in the series element portion 401b, the current of the direct current flowing through the magnetoresistive effect element 402b. When the density is J0, the current density Ja of the direct current flowing through the magnetoresistive effect element 402a is smaller than J0 (= Jb), and as shown in FIG. 7B, fa can be made closer to fb (= fb0). Similarly, when the resistance value Rc of the resistance element 403c included in the series element portion 401c is smaller than the resistance value Rb of the resistance element 403b included in the series element portion 401b, the direct current flowing through the magnetoresistive effect element 402b When the current density of J0 is J0, the current density Jc of the direct current flowing through the magnetoresistive effect element 402c is larger than J0 (= Jb), and as shown in FIG. 7C, fc may be close to fb (= fb0). it can. Accordingly, the DC current J0 having the same current density is supplied to each of the magnetoresistive elements 402a, 402b, and 402c in a state where the magnetic field applied by the magnetic field applying mechanism 407 is applied to each of the magnetoresistive elements 402a, 402b, and 402c. The magnitude relationship (fa0 <fb0 <fc0) of the spin torque oscillation frequencies fa0, fb0, fc0 of the magnetoresistive effect elements 402a, 402b, 402c and the direct current that actually flows through the magnetoresistive effect elements 402a, 402b, 402c. Since the magnitude relationships of the current densities Ja, Jb, and Jc are the same, that is, Ja <Jb <Jc, the oscillation output from the magnetoresistive effect device 400 can be increased as shown in FIG. 7D. Become. Here, the resistance value Ra of the resistance element 403a is Ja≈J1 as shown in FIG. 6, and the resistance value Rc of the resistance element 403c is Jc≈J2 as shown in FIG. It is desirable to be determined. As described above, according to the magnetoresistive effect device 400, the variation in the frequency of the output current due to the variation in the planar view shape of each of the magnetoresistive elements 402a, 402b, and 402c is suppressed, and a large oscillation output can be obtained.

  In the magnetoresistive effect device 400, since the serial element portions 401a, 401b, and 401c include the resistive elements 403a, 403b, and 403c connected in series with the magnetoresistive effect elements 402a, 402b, and 402c, the resistive elements 403a, 403b, Since the resistance values of the series element portions 401a, 401b, and 401c can be adjusted by 403c, the adjustment of the spin torque resonance frequency of the magnetoresistive effect elements 402a, 402b, and 402c by the resistance value is easy.

  Furthermore, since each magnetoresistive effect element 402a, 402b, 402c has the same film structure, all the magnetoresistive effect elements 402a, 402b, 402c can be formed into a thin film at once on one wafer. The magnetoresistive device 400 is easy to manufacture.

  In the second embodiment, the resistance elements 403a, 403b, and 403c are included in the series element portions 401a, 401b, and 401c, respectively, but the resistance elements 403a, 403b, and 403c are not necessarily included in the series element portions 401a, 401b, and 401c. It does not have to be. For example, the serial element portion 401c may be configured by only the magnetoresistive element 402c. In this case, although the resistance element is not included in the series element portion 401c, the resistance value of the resistance element of the series element portion 401c is considered to be the minimum, and the magnitude relation of the resistance value of the resistance element of each series element portion is considered.

  In the second embodiment, the magnetoresistive elements 402a, 402b, and 402c have the same film structure, but the magnetoresistive elements 402a, 402b, and 402c may not have the same film structure. For example, the resistance values of the magnetoresistive elements 402a, 402b, and 402c are made different by changing the thickness of the spacer layer 105 between the magnetoresistive elements 402a, 402b, and 402c, so that the resistive elements 403a, 403b, and 403c are changed. The magnitude relationship between the current densities Ja, Jb, and Jc of the direct currents that actually flow through the magnetoresistive elements 402a, 402b, and 402c may be adjusted.

  In the first embodiment, an example in which the magnetic field strength applied to each magnetoresistive effect element is different will be described. In the second embodiment, the aspect ratio of the planar view shape of a plane parallel to the film surface of each magnetoresistive effect element is described. Although described in different examples, the magnetic field strength applied to each magnetoresistive effect element may be different, and the aspect ratio of the planar view shape of the plane parallel to the film surface of each magnetoresistive effect element may be different. Even in such a case, each magnetoresistive effect element when a direct current having the same current density is passed through each magnetoresistive effect element in a state where the magnetic field applied by the magnetic field application mechanism is applied to each magnetoresistive effect element. Since the magnitude relation of the spin torque oscillation frequency of the current and the magnitude relation of the current density of the direct current flowing through each magnetoresistive effect element are the same, a large oscillation output can be obtained from the magnetoresistive effect device.

(Embodiment 3)
FIG. 8 is a cross-sectional view of a magnetoresistive effect device 800 according to Embodiment 3 of the present invention. In the magnetoresistive effect device 800, the description common to the magnetoresistive effect device 100 of the first embodiment is omitted as appropriate. Elements common to the magnetoresistive effect device 100 of Embodiment 1 are denoted by the same reference numerals, and description of common elements is omitted. The magnetoresistive effect device 800 according to the third embodiment includes serial element portions 801a, 801b, and 801c in place of the serial element portions 101a, 101b, and 101c in the magnetoresistive effect device 100 according to the first embodiment, and includes the magnetoresistive effect element 102a. , 102b, and 102c are replaced with magnetoresistive elements 802a, 802b, and 802c, and the resistive elements 103a, 103b, and 103c are replaced with resistive elements 803a, 803b, and 803c.

  The magnetoresistive effect device 800 includes a plurality of series element portions 801 including a magnetoresistive effect element 802 and a resistance element 803, and the magnetic field application mechanism 107. The magnetoresistive effect element 802 includes a spacer layer 805 including magnetic nanocontacts 814 and a magnetization fixed layer 104 and a magnetization free layer 106 via the spacer layer 805. More specifically, the magnetoresistive effect device 800 includes three series element portions 801a, 801b, and 801c. The series element portion 801a includes a magnetoresistive effect element 802a and a resistance element 803a, and the series element portion 801b is a magnetoresistive element. The effect element 802b and the resistance element 803b are included, and the series element portion 801c includes the magnetoresistance effect element 802c and the resistance element 803c. The magnetoresistive elements 802a, 802b and 802c all have the same configuration (the same film structure, shape and size).

  The spin torque oscillation of the magnetoresistive effect element 802 according to this embodiment will be described. Oscillation is a phenomenon in which electrical vibration is induced by a non-vibrating direct current.

  The oscillation of the magnetoresistive effect element 802 is caused by the magnetization dynamics of the magnetic layer of the magnetoresistive effect element 802. At the same time as applying the magnetic field by the magnetic field applying mechanism 107, the magnetization free layer 106 is directed in the direction of the magnetization fixed layer 104 through the magnetic nanocontact 814 in the spacer layer 805 in the direction perpendicular to the laminated surface of the magnetoresistive effect element 802. By applying a direct current, a spin-polarized current flows in the magnetic nanocontact 814, and a spin precession generated in the magnetic nanocontact 814 causes a magnetoresistive effect in which the resistance value changes at a high frequency. An alternating current that oscillates at a high frequency of about 100 MHz to several tens of THz is generated. The magnetoresistive elements 802a, 802b, and 802c each have a circular shape in plan view of a plane parallel to the film surface.

The spacer layer 805 including the magnetic nanocontact 814 has a function of obtaining a magnetoresistance effect by causing the magnetization of the magnetization fixed layer 104 and the magnetization of the magnetization free layer 106 to interact with each other. The magnetic nanocontact 814 is a nano-sized current confinement path made of a conductive material from the magnetization fixed layer 104 to the magnetization free layer 106. A nonmagnetic insulating material such as AlO _x (aluminum oxide), MgO (magnesium oxide), or MgAl ₂ O _4, or a magnetic insulating material is used as the material of the portion 815 around the magnetic nanocontact 814 in the spacer layer 805. be able to. As a material of the magnetic nanocontact 814, a magnetic conductive material such as an alloy of Fe and Co, an alloy of Fe, Co, and Al, or an alloy of Fe, Co, Al, and Si can be used.

  The resistance values of the resistance elements 803a, 803b, and 803c are Ra, Rb, and Rc. In the magnetoresistance effect device 800, Ra <Rb <Rc. The magnetoresistive effect elements 802a, 802b, and 802c have the same film structure and are connected in parallel. Therefore, if Ra = Rb = Rc, the magnetoresistive effect elements 802a, 802b, and 802c have magnetic nanostructures. A current having the same current density flows through the contact 814. In the magnetoresistive effect device 800, since Ra <Rb <Rc, the current densities of the direct currents that actually flow through the magnetic nanocontacts 814 of the magnetoresistive effect elements 802a, 802b, 802c are Ja, Jb, Jc, respectively. Then, Jc <Jb <Ja.

  The strength of the magnetic field generated by the magnetic field application mechanism 107 is inversely proportional to the distance from the magnetic field application mechanism 107, and the magnetic field strength of the place where the magnetoresistive effect element 802a is arranged is Ha, and the magnetoresistive effect element 802b is arranged. Assuming that the magnetic field strength at the location where the magnetic field strength is Hb and the magnetic field strength where the magnetoresistive effect element 802c is disposed is Hc, Ha <Hb <Hc. That is, in the magnetoresistive effect device 800, the magnitude relationship (Ha <Hb <Hc) of the magnetic field strengths Ha, Hb, and Hc applied to the magnetoresistive effect elements 802a, 802b, and 802c, and the magnetoresistive effect elements 802a, The magnitude relationships (Ra <Rb <Rc) of the resistance values Ra, Rb, Rc of the resistance elements 803a, 803b, 803c of the series element portions 801a, 801b, 801c corresponding to 802b, 802c are the same, and each magnetic field The magnitude relationship (Ha <Hb <Hc) of the magnetic field strengths Ha, Hb, Hc applied to the resistance effect elements 802a, 802b, 802c, and the magnetic nanocontacts 814 of the magnetoresistance effect elements 802a, 802b, 802c are actually shown. The magnitude relationship (Jc <Jb <Ja) of the current densities Ja, Jb and Jc of the flowing direct current is opposite. Here, the spin torque oscillation frequencies of the magnetoresistive effect elements 802a, 802b, and 802c when DC currents having the same current density J0 are passed through the magnetic nanocontacts 814 of the magnetoresistive effect elements 802a, 802b, and 802c, respectively. Assuming fa0, fb0, and fc0, the spin torque resonance frequency of the magnetoresistive element increases as the magnetic field applied to the magnetoresistive element increases, so that fa0 <fb0 <fc0.

  FIG. 9 shows the relationship between the current density J of the direct current flowing through the magnetic nanocontact 814 of each of the magnetoresistive elements 802a, 802b, and 802c and the spin torque resonance frequency f. A straight line A in FIG. 9 represents the relationship between the current density J of the direct current flowing through the magnetic nanocontact 814 of the magnetoresistive effect element 802a and the spin torque resonance frequency fa of the magnetoresistive effect element 802a. A straight line B in FIG. 9 shows the relationship between the current density J of the direct current flowing through the magnetic nanocontact 814 of the magnetoresistive effect element 802b and the spin torque resonance frequency fb of the magnetoresistive effect element 802b. A straight line C in FIG. 9 indicates the relationship between the current density J of the direct current flowing through the magnetic nanocontact 814 of the magnetoresistive effect element 802c and the spin torque resonance frequency fc of the magnetoresistive effect element 802c. As shown in FIG. 9, in the magnetoresistive effect element including the magnetic nanocontact in the spacer layer, the spin torque resonance frequency of the magnetoresistive effect element increases as the current density of the direct current flowing through the magnetic nanocontact increases. (The magnetoresistive effect element having magnetic nanocontacts in the spacer layer has a current density region in which the spin torque resonance frequency of the magnetoresistive effect element increases as the current density of the direct current flowing through the magnetic nanocontact increases. Used in).

  10A, 10B, 10C, and 10D show the frequency distribution of the oscillation output from the magnetoresistive device 800. FIG. FIG. 10A shows a case where the resistance values of the resistance elements 803a, 803b, and 803c are Ra = Rb = Rc, and the current density of the direct current flowing through the magnetic nanocontacts 814 of the magnetoresistance effect elements 802a, 802b, and 802c is J0. 5 is a frequency distribution of oscillation output from the magnetoresistive effect device 800. At this time, as shown in FIG. 10A, a high output cannot be obtained due to variations in the frequency of the output current.

  First, when the resistance value Ra of the resistance element 803a included in the series element portion 801a is smaller than the resistance value Rb of the resistance element 803b included in the series element portion 801b, the magnetic nanocontact 814 of the magnetoresistance effect element 802b is changed. When the current density of the flowing direct current is J0, the current density Ja of the direct current flowing through the magnetic nanocontact 814 of the magnetoresistive effect element 802a is larger than J0 (= Jb), and as shown in FIG. (= Fb0). Similarly, when the resistance value Rc of the resistance element 803c included in the series element portion 801c is larger than the resistance value Rb of the resistance element 803b included in the series element portion 801b, the magnetic nanocontact of the magnetoresistive effect element 102b. When the current density of the direct current flowing through 814 is J0, the current density of the direct current flowing through the magnetic nanocontact 814 of the magnetoresistive effect element 802c is smaller than J0 (= Jb), and as shown in FIG. It can be close to fb (= fb0). Therefore, in the state where the magnetic field applied by the magnetic field application mechanism 807 is applied to the magnetoresistive elements 802a, 802b, and 802c, the magnetic nanocontacts 814 of the magnetoresistive elements 802a, 802b, and 802c have the same current density. The magnitude relation (fa0 <fb0 <fc0) of the spin torque oscillation frequencies fa0, fb0, fc0 of the magnetoresistive effect elements 802a, 802b, 802c when the direct current J0 is passed, and the actual magnetoresistive effect elements 802a, 802b , 802c magnetic nanocontacts 814, the magnitude relation of the current density Ja, Jb, Jc of the direct current is opposite, that is, Jc <Jb <Ja, so that as shown in FIG. The oscillation output can be increased. Here, the resistance value Ra of the resistance element 803a is Ja≈J2 as shown in FIG. 9, and the resistance value Rc of the resistance element 803c is Jc≈J1 as shown in FIG. It is desirable to be determined. As described above, according to the magnetoresistive effect device 800, the variation in the frequency of the output current due to the variation in the strength of the magnetic field applied by the magnetic field application mechanism 807 is suppressed, and a large oscillation output can be obtained.

  In the magnetoresistive effect device 800, since the serial element portions 801a, 801b, 801c include the resistive elements 803a, 803b, 803c connected in series with the magnetoresistive effect elements 802a, 802b, 802c, the resistive elements 803a, 803b, Since the resistance value of each of the serial element portions 801a, 801b, and 801c can be adjusted by 803c, the adjustment of the spin torque resonance frequency of the magnetoresistance effect elements 802a, 802b, and 802c by the resistance value is easy.

  Furthermore, since the magnetoresistive elements 802a, 802b, and 802c have the same film structure, all the magnetoresistive elements 802a, 802b, and 802c can be collectively formed into a thin film on one wafer. The magnetoresistive device 800 is easy to manufacture.

  In the third embodiment, the resistance elements 803a, 803b, and 803c are included in the series element portions 801a, 801b, and 801c, respectively, but the resistance elements 803a, 803b, and 803c are not necessarily included in the series element portions 801a, 801b, and 801c. It does not have to be. For example, the serial element portion 801a may be configured by only the magnetoresistive element 802a. In this case, although the resistance element is not included in the series element portion 801a, the resistance value of the resistance element of the series element portion 801a is considered to be the minimum, and the magnitude relation of the resistance value of the resistance element of each series element portion is considered.

  In the third embodiment, the magnetoresistive elements 802a, 802b, and 802c have the same film structure, but the magnetoresistive elements 802a, 802b, and 802c do not have to have the same film structure. For example, the resistance values of the magnetoresistive elements 802a, 802b, and 802c are made different by changing the thickness of the spacer layer 805 between the magnetoresistive elements 802a, 802b, and 802c, so that the resistive elements 803a, 803b, and 803c are changed. The magnitude relationship between the current densities Ja, Jb, and Jc of the DC current that actually flows through the magnetic nanocontacts 814 of the magnetoresistive elements 802a, 802b, and 802c may be adjusted without using.

  In the first to third embodiments, the example in which the direct current is passed from the magnetization free layer 106 to the magnetization fixed layer 104 has been described. However, the direct current is caused to flow from the magnetization fixed layer 104 to the magnetization free layer 106. Also good.

  As described above, the magnetoresistive effect device according to the present invention can be used for an oscillator or the like.

100, 400, 800 Magnetoresistive devices 101, 101a, 101b, 101c, 401, 401a, 401b, 401c, 801a, 801b, 801c Series element portions 102, 102a, 102b, 102c, 402, 402a, 402b, 402c, 802a , 802b, 802c Magnetoresistive element 103, 103a, 103b, 103c, 403, 403a, 403b, 403c, 803a, 803b, 803c Resistive element 104 Magnetization fixed layer 105, 805 Spacer layer 106 Magnetization free layer 107, 407 Magnetic field application mechanism 108 Signal electrode layer 109 Ground electrode layer 110 Insulator layer 111 DC current input terminal 112 AC current output terminal 113 Semiconductor substrate 814 Magnetic nanocontact

Claims (6)

A magnetoresistive effect element including a spacer layer made of a single material, a magnetization fixed layer and a magnetization free layer via the spacer layer, and a magnetic field application mechanism for applying a magnetic field to the magnetoresistive effect element,
A plurality of series element portions including the magnetoresistive effect element are connected in parallel,
Variation in frequency of output current from each magnetoresistive effect element when a direct current having the same current density is passed through each magnetoresistive effect element with the magnetic field applied to each magnetoresistive effect element Than the current of the same magnitude in each magnetoresistive effect element in a state where the magnetic field is applied to each magnetoresistive effect element so that the variation in frequency of the output current from each magnetoresistive effect element becomes smaller. The magnitude relationship of the spin torque resonance frequency of each magnetoresistive effect element when a direct current of density is passed is the same as the magnitude relationship of the current density of the DC current actually flowing through each magnetoresistive effect element. And magnetoresistive device.   The magnetoresistive effect device according to claim 1, wherein at least one of the series element portions includes a resistive element connected in series with the magnetoresistive effect element.   The magnetoresistive effect device according to claim 1, wherein the magnetoresistive effect elements have the same film structure. A magnetoresistive effect element including a spacer layer provided with magnetic nanocontacts, a magnetization fixed layer and a magnetization free layer via the spacer layer, and a magnetic field application mechanism for applying a magnetic field to the magnetoresistive effect element,
A plurality of series element portions including the magnetoresistive effect element are connected in parallel,
Output from each magnetoresistive effect element when a direct current having the same current density is passed through the magnetic nanocontact of each magnetoresistive effect element in a state where the magnetic field is applied to each magnetoresistive effect element Each of the magnetoresistive effect elements in a state in which the magnetic field is applied to each of the magnetoresistive effect elements so that the variation in the frequency of the output current from each of the magnetoresistive effect elements is smaller than the variation of the current frequency . The magnitude relation of the spin torque resonance frequency of each magnetoresistive effect element when a direct current of the same current density is passed through the magnetic nanocontact, and the actual flow through the magnetic nanocontact of each magnetoresistive effect element A magnetoresistive device characterized in that the magnitude relation of the current density of a direct current is opposite.   The magnetoresistive effect device according to claim 4, wherein at least one of the series element portions includes a resistive element connected in series with the magnetoresistive effect element.   6. The magnetoresistive effect device according to claim 4, wherein the magnetoresistive effect elements have the same film structure.

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