CN102978702B - Compound barium borofluoride, barium borofluoride non-linear optical crystal, and preparation method and use of the barium borofluoride non-linear optical crystal - Google Patents

Abstract

A compound barium fluoroborate and barium fluoroborate nonlinear optical crystal, its preparation method and application, the chemical formula of the compound barium fluoroborate and its nonlinear optical crystal is Ba ₃ B ₆ O ₁₁ F ₂ , the crystal belongs to the monoclinic system, and the space Group P2(1), the unit cell parameter is beta = 101.351(4) deg., Molecular weight 690.88. The frequency doubling effect of its powder is three times that of KDP (KH ₂ PO ₄ ). The compound barium fluoroborate is synthesized by solid-state reaction method; the nonlinear optical crystal of barium fluoroborate is grown by high-temperature melt method. The nonlinear optical crystal of barium fluoroborate It has high mechanical hardness, is easy to cut, polish and store, and is widely used in the preparation of nonlinear optical devices such as frequency doubling generators, up-frequency converters, down-frequency converters or optical parametric oscillators.

Description

Compound barium fluoroborate and barium fluoroborate nonlinear optical crystal, preparation method and use

technical field

The invention relates to compound barium fluoroborate and barium fluoroborate nonlinear optical crystal with _the chemical formula of _Ba3B6O11F2 , a preparation _{method of} the crystal and a nonlinear optical device made of the crystal.

Background technique

At present, the main nonlinear optical materials are: BBO (β-BBO), LBO (LiB ₃ O ₅ ) crystal, CBO (CsB ₃ O ₅ ) crystal, CLBO (CsLiB ₆ O ₁₀ ) crystal and KBBF (KBe ₂ BO ₃ F ₂ ) crystals. Although the crystal growth technology of these materials has become increasingly mature, there are still obvious deficiencies: such as crystal deliquescence, long growth cycle, serious layered growth habit and high price. Therefore, finding new nonlinear optical crystal materials is still a very important and arduous work.

Therefore, in recent years, when developing new nonlinear optical crystals, not only the optical properties and mechanical properties of the crystals are paid attention to, but also the preparation characteristics of the crystals are paid more and more attention. It is hoped that the new crystal materials can be easily prepared, and large-size high-quality crystals can be obtained at low prices. Nonlinear Optical Crystals. Under the guidance of the design concept of introducing alkaline earth metal cations and halide ions into the boron-oxygen framework to improve its performance, the anion is based on the boron-oxygen functional unit, which has a large band gap, a small probability of two-photon absorption, and a high laser damage threshold; It is beneficial to obtain a strong nonlinear optical effect; the BO bond is conducive to the transmission of broadband light. The cations are alkaline earth metal ions, which have no transition of d ₀ electrons in the ultraviolet region, which is conducive to the transmission of ultraviolet light, and the introduction of halogen ions broadens the range of light transmission.

Contents of the invention

The object of the present invention is to provide a barium fluoroborate compound and a barium fluoroborate nonlinear optical crystal, both of which have the chemical formula Ba ₃ B ₆ O ₁₁ F ₂ .

Another object of the present invention is to provide a preparation method for synthesizing compounds by solid-state reaction method and growing barium fluoroborate nonlinear optical crystal by high-temperature melt method.

Another object of the present invention is to provide a use of a barium fluoroborate nonlinear optical device for preparing a frequency multiplication generator, an up or down frequency converter or an optical parametric oscillator.

A barium fluoroborate compound described in the present invention has a chemical formula of Ba ₃ B ₆ O ₁₁ F ₂ and a molecular weight of 690.88. The compound is synthesized by a solid phase reaction method.

A compound barium fluoroborate nonlinear optical crystal, the crystal chemical formula is Ba ₃ B ₆ O ₁₁ F ₂ , does not have a center of symmetry, belongs to the monoclinic system, space group P2(1), and the unit cell parameter is β=101.351(4)°.Z=2, Its powder frequency doubling effect is three times that of KDP (KH ₂ PO ₄ ).

The preparation method of the barium fluoroborate nonlinear optical crystal adopts the solid-state reaction method to synthesize the compound and the high-temperature melt method to grow the barium fluoroborate nonlinear optical crystal, and the specific operation is carried out according to the following steps:

a. Uniformly mix the single-phase polycrystalline powder of the barium fluoroborate compound with the flux, heat it to a temperature of 650-900°C at a heating rate of 1-30°C/h, and keep the temperature constant for 5-80 hours to obtain a mixed melt, Then lower the temperature to a temperature of 610-830°C, wherein the molar ratio of the barium fluoroborate compound single-phase polycrystalline powder to the flux is 1:1-6;

Or directly mix the barium-containing compound, barium fluoride, boric acid and flux evenly, heat it to a temperature of 650-900°C at a heating rate of 1-30°C/h, and keep the temperature constant for 5-80 hours to obtain a mixed melt, Then cool down to a temperature of 610-830°C, wherein the molar ratio of the barium-containing compound, barium fluoride and boric acid to the flux is 2:1:6:1-6;

b. Preparation of barium fluoroborate seed crystals: Slowly lower the mixed melt obtained in step a to room temperature at a rate of 0.5-10°C/h, and spontaneously crystallize to obtain barium fluoroborate seed crystals;

c. Put the crucible containing the mixed melt obtained in step a into the crystal growth furnace, fix the seed crystal obtained in step b on the seed crystal rod, lower the seed crystal from the top of the crystal growth furnace, and preheat the seed crystal After 5-60 minutes, the seed crystal is lowered to contact the liquid surface of the mixed melt or melted back in the mixed melt, the temperature is kept constant for 5-60 minutes, and the temperature is lowered to the saturation temperature at a rate of 1-60°C/h.

d. Slowly lower the temperature at a rate of 0.1-5°C/day, and rotate the seed rod at a speed of 0-60rpm to grow the crystal. After the single crystal grows to the required size, lift the crystal from the surface of the mixed melt, and The temperature is lowered to room temperature at a rate of 1-80° C./h, and then the crystal is taken out from the furnace to obtain the barium fluoroborate nonlinear optical crystal.

The barium-containing compound described in step a is barium carbonate, barium nitrate, barium oxide, barium hydroxide, barium bicarbonate or barium oxalate.

The flux in step a is NaF-H ₃ BO ₃ , H ₃ BO ₃ -Na ₂ O, Na ₂ O-PbO, LiF-PbO, NaF-PbO or H ₃ BO ₃ -PbO.

The molar ratio of NaF to H ₃ BO ₃ in flux NaF-H ₃ BO ₃ system is 1-5:3-6; the molar ratio of fluoride to lead oxide in LiF-PbO or NaF-PbO system is 1-5: 1-6; the molar ratio of boric acid to oxide in H ₃ BO ₃ -PbO or H ₃ BO ₃ -Na ₂ O system is 2-5:1-5; the ratio of sodium oxide to lead oxide in Na ₂ O-PbO system The molar ratio is 1-5:0.1-6.

The use of the barium fluoroborate nonlinear optical crystal is used to prepare a frequency doubling generator, an up-frequency converter, a down-frequency converter or an optical parametric oscillator.

The barium fluoroborate compound provided by the present invention has a chemical formula of Ba ₃ B ₆ O ₁₁ F ₂ ; the barium fluoroborate compound is prepared by a solid-state reaction method according to the following chemical reaction formula:

(1) 2BaCO ₃ +BaF ₂ +6H ₃ BO ₃ →Ba ₃ B ₆ O ₁₁ F ₂ +2CO ₂ ↑+9H ₂ O↑

(2)2Ba(NO ₃ ) ₂ +BaF ₂ +6H ₃ BO ₃ →Ba ₃ B ₆ O ₁₁ F ₂ +2NO ₂ ↑+9H ₂ O↑+3O ₂ ↑

(3) 2BaO+BaF ₂ +6H ₃ BO ₃ →Ba ₃ B ₆ O ₁₁ F ₂ +9H ₂ O↑

(4) 2Ba(OH) ₂ +BaF ₂ +6H ₃ BO ₃ →Ba ₃ B ₆ O ₁₁ F ₂ +11H ₂ O↑

(5) 2Ba(HCO ₃ ) ₂ +BaF ₂ +6H ₃ BO ₃ →Ba ₃ B ₆ O ₁₁ F ₂ +4CO ₂ ↑+11H ₂ O↑

(6) 2BaCO ₃ +BaF ₂ +3B ₂ O ₃ →Ba ₃ B ₆ O ₁₁ F ₂ +2CO ₂ ↑

(7)2Ba(NO ₃ ) ₂ +BaF ₂ +3B ₂ O ₃ →Ba ₃ B ₆ O ₁₁ F ₂ +4NO ₂ ↑+O ₂ ↑

(8) 2BaO+BaF ₂ +3B ₂ O ₃ →Ba ₃ B ₆ O ₁₁ F ₂

(9) 2Ba(OH) ₂ +BaF ₂ +3B ₂ O ₃ →Ba ₃ B ₆ O ₁₁ F ₂ +2H ₂ O↑

(10)2Ba(HCO ₃ ) ₂ +BaF ₂ +3B ₂ O ₃ →Ba ₃ B ₆ O ₁₁ F ₂ +4CO ₂ ↑+2H ₂ O↑

(11) 2BaC ₂ O ₄ +BaF ₂ +3B ₂ O ₃ →Ba ₃ B ₆ O ₁₁ F ₂ +2CO ₂ ↑+2CO.

The obtained crystal has the advantages of relatively wide light transmission band, high hardness, good mechanical properties, not easy to break and deliquescence, easy to process and store, and the like. The nonlinear optical device made of the compound barium fluoroborate nonlinear optical crystal obtained by the method of the present invention uses a Nd:YAG Q-switched laser as a light source at room temperature, the incident wavelength is 1064nm infrared light, and the output wavelength is 532nm Green laser, the laser intensity is equivalent to 3 times of KDP (KH ₂ PO ₄ ).

Description of drawings

Fig. 1 is an x-ray diffraction pattern of Ba ₃ B ₆ O ₁₁ F ₂ powder of the present invention.

Fig. 2 is the working principle diagram of the nonlinear optical device made of Ba ₃ B ₆ O ₁₁ F ₂ crystal of the present invention, wherein 1 is a laser, 2 is an emitting light beam, 3 is a Ba ₃ B ₆ O ₁₁ F ₂ crystal, and 4 is an outgoing beam, 5 is a filter.

Detailed ways

The present invention is described in detail below in conjunction with accompanying drawing and embodiment:

Example 1:

According to the reaction formula: 2BaCO ₃ +BaF ₂ +6H ₃ BO ₃ →Ba ₃ B ₆ O ₁₁ F ₂ +2CO ₂ ↑+9H ₂ O↑ to synthesize the Ba ₃ B ₆ O ₁₁ F ₂ compound:

Weigh BaCO ₃ , BaF ₂ , H ₃ BO ₃ in a molar ratio of 2:1:6 and put them into a mortar, mix and grind them carefully, then put them into a corundum crucible with an opening of Φ100mm×100mm, and put them into a muffle furnace , slowly heat up to 550°C, keep the temperature for 24 hours, cool to room temperature, take it out and put it into the muffle furnace after the second grinding, then heat up to 650°C, keep the temperature for 24 hours, cool to room temperature, take it out after the third grinding Put it into a muffle furnace, raise the temperature to 780°C, keep the temperature constant for 48 hours, take out the single-phase polycrystalline powder of barium fluoroborate compound obtained by grinding, and conduct X-ray analysis on the product. The obtained X-ray spectrum is consistent with that of barium fluoroborate Ba The X-ray spectra obtained from the single crystal structure of ₃ B ₆ O ₁₁ F ₂ are consistent;

The obtained barium fluoroborate Ba ₃ B ₆ O ₁₁ F ₂ compound single-phase polycrystalline powder and flux NaF-H ₃ BO ₃ are molar ratio Ba ₃ B ₆ O ₁₁ F ₂ : NaF-H ₃ BO ₃ =1: 3. The molar ratio of NaF and H ₃ BO ₃ is 3:4, mix them, put them into a Φ80mm×80mm open platinum crucible, heat it to 780°C at a heating rate of 30°C/h, and keep the temperature constant for 15 hours , to obtain a mixed melt, and then lower the temperature to 735°C;

Slowly cool down to room temperature at a rate of 0.5°C/h, and spontaneously crystallize to obtain barium fluoroborate seed crystals;

Crystal growth in the compound melt: fix the obtained Ba ₃ B ₆ O ₁₁ F ₂ seed crystal on the seed rod and lower the seed crystal from the top of the crystal growth furnace, first preheat the seed crystal on the surface of the mixed melt for 10 minutes, Immerse in the liquid surface, make the seed crystal remelt in the mixed melt, keep the temperature for 30 minutes, and quickly cool down to the saturation temperature of 730°C;

Then cool down at a rate of 2°C/day, and rotate the seed rod at a speed of 10 rpm. After the crystal growth is completed, the crystal is removed from the liquid surface, and the temperature is lowered to room temperature at a rate of 10°C/hour, and a size of 56mm× 40mm×30mm Ba ₃ B ₆ O ₁₁ F ₂ crystal.

The raw material barium carbonate in the reaction formula can be replaced by barium oxide or barium nitrate or barium oxalate or barium hydroxide or barium bicarbonate, and boric acid can be replaced by boron oxide.

Example 2:

According to the reaction formula: 2Ba(NO ₃ ) ₂ +BaF ₂ +6H ₃ BO ₃ →Ba ₃ B ₆ O ₁₁ F ₂ +2NO ₂ ↑+9H ₂ O↑+3O ₂ ↑Synthesis of Ba ₃ B ₆ O ₁₁ F ₂ compound :

Weigh Ba(NO ₃ ) ₂ , BaF ₂ , H ₃ BO ₃ raw materials directly in a molar ratio of 2:1:6, and mix the weighed raw materials with flux Na ₂ OH ₃ BO ₃ in a molar ratio of 1:4 The molar ratio of Na ₂ O to H ₃ BO ₃ is 2:5, put it into a Φ80mm×80mm open platinum crucible, raise the temperature to 745°C, and keep the temperature constant for 60 hours to obtain a mixed melt, and cool it down to the temperature 715°C;

Slowly cool down to room temperature at a rate of 1.5°C/h, and spontaneously crystallize to obtain barium fluoroborate seed crystals;

Fix the obtained Ba ₃ B ₆ O ₁₁ F ₂ seed crystal on the seed crystal rod and lower the seed crystal from the top of the crystal growth furnace. Remelt in the mixed melt, keep the temperature for 30 minutes, and quickly cool down to the saturation temperature of 710°C;

Slowly lower the temperature at a rate of 1°C/day without rotating the seed rod. After the crystal grows to the required size, lift the crystal from the surface of the melt and lower it to room temperature at a rate of 20°C/h, then remove the crystal from the Take it out from the furnace to obtain a Ba ₃ B ₆ O ₁₁ F ₂ crystal with a size of 36mm×22mm×15mm.

The raw material barium nitrate in the reaction formula can be replaced by barium carbonate or barium oxide or barium oxalate or barium hydroxide or barium bicarbonate, and boric acid can be replaced by boron oxide.

Example 3:

According to the reaction formula: 2BaO+BaF ₂ +6H ₃ BO ₃ →Ba ₃ B ₆ O ₁₁ F ₂ +9H ₂ O↑ to synthesize the Ba ₃ B ₆ O ₁₁ F ₂ compound:

Put BaO, BaF ₂ , H ₃ BO ₃ into a mortar at a molar ratio of 2:1:6, mix and grind carefully, then put it into a corundum crucible with an opening of Φ100mm×100mm, press it tightly, and put it into a muffle In the furnace, slowly raise the temperature to 550°C and keep the temperature constant for 24 hours. After cooling, take out the crucible. At this time, the sample is relatively loose. Then take out the sample and re-grind it evenly, and then put it in the crucible. hour, take it out, put it into a mortar, mash and grind it to get the Ba ₃ B ₆ O ₁₁ F ₂ compound, and carry out X-ray analysis on the product, and the obtained X-ray spectrum is consistent with that of barium fluoroborate Ba ₃ B ₆ O ₁₁ F ₂ The X-ray spectra obtained from the single crystal structure are consistent;

Mix the synthesized Ba ₃ B ₆ O ₁₁ F ₂ compound with the flux LiF-PbO at a molar ratio of 1:5, where the molar ratio of LiF to PbO is 1:1, and put them into a Φ80mm×80mm open platinum crucible In the process, the temperature was raised to 720°C, and the temperature was kept constant for 80 hours to obtain a mixed melt, and then lowered to a temperature of 660°C;

Slowly cool down to room temperature at a rate of 2.5°C/h, and spontaneously crystallize to obtain barium fluoroborate seed crystals;

Fix the obtained seed crystal on the seed crystal rod and lower the seed crystal from the top of the crystal growth furnace, first preheat the seed crystal on the surface of the mixed melt for 10 minutes, and partially immerse it under the liquid surface, so that the seed crystal can be refluxed in the mixed melt Melt, keep the temperature for 20 minutes, and quickly cool down to the saturation temperature of 650°C;

Slowly lower the temperature at a rate of 2°C/day, and rotate the seed rod at a speed of 30 rpm. After the crystal grows to the desired size, lift the crystal from the surface of the melt, and lower it to room temperature at a rate of 30°C/h, and then The crystal is taken out from the furnace to obtain a Ba ₃ B ₆ O ₁₁ F ₂ crystal with a size of 33mm×30mm×20mm.

The raw material barium oxide in the reaction formula can be replaced by barium carbonate or barium nitrate or barium oxalate or barium hydroxide or barium bicarbonate, and boric acid can be replaced by boron oxide.

Example 4:

According to the reaction formula: 2Ba(OH) ₂ +BaF ₂ +6H ₃ BO ₃ →Ba ₃ B ₆ O ₁₁ F ₂ +11H ₂ O↑ to synthesize Ba ₃ B ₆ O ₁₁ F ₂ compound:

Weigh the raw materials directly with Ba(OH) ₂ , BaF ₂ and H ₃ BO ₃ in a molar ratio of 2:1:6, and mix the weighed raw materials with flux NaF-H ₃ BO ₃ in a molar ratio of 1:3 , _wherein the molar ratio of NaF to _H3BO3 is 1:1, put it into a Φ80mm×80mm open platinum crucible, heat up to a temperature of 765°C, keep the temperature at a constant temperature for 10 hours to obtain a mixed melt, and cool down to a temperature of 715°C;

Slowly cool down to room temperature at a rate of 2.5°C/h, and spontaneously crystallize to obtain barium fluoroborate seed crystals;

Fix the obtained Ba ₃ B ₆ O ₁₁ F ₂ seed crystal on the seed crystal rod and lower the seed crystal from the top of the crystal growth furnace. Melt back in the mixed melt, keep the temperature for 5 minutes, and quickly cool down to the saturation temperature of 700°C;

Then slowly lower the temperature at a rate of 2°C/day, and rotate the seed rod at a speed of 50 rpm. After the crystal grows to the desired size, lift the crystal from the surface of the melt, and lower it to room temperature at a rate of 60°C/h, and then The crystal is taken out from the furnace to obtain a Ba ₃ B ₆ O ₁₁ F ₂ crystal with a size of 30mm×28mm×15mm.

The raw material barium hydroxide in the reaction formula can be replaced by barium carbonate or barium nitrate or barium oxalate or barium oxide or barium bicarbonate, and boric acid can be replaced by boron oxide.

Example 5:

According to the reaction formula: 2Ba(HCO ₃ ) ₂ +BaF ₂ +6H ₃ BO ₃ →Ba ₃ B ₆ O ₁₁ F ₂ +4CO ₂ ↑+11H ₂ O↑ to synthesize the Ba(HCO ₃ ) ₂ compound:

Ba(HCO ₃ ) ₂ , BaF ₂ , H ₃ BO ₃ are directly weighed as raw materials in a molar ratio of 2:1:6, and mixed with the weighed raw materials and flux NaF-PbO in a molar ratio of 1:6, Among them, the molar ratio of NaF and PbO is 3:1, put it into an open platinum crucible of Φ80mm×80mm, heat up to a temperature of 680°C, keep the temperature for 60 hours to obtain a mixed melt, and then lower it to a temperature of 620°C;

Slowly cool down to room temperature at a rate of 3.5°C/h, and spontaneously crystallize to obtain barium fluoroborate seed crystals;

Fix the obtained Ba ₃ B ₆ O ₁₁ F ₂ seed crystal on the seed crystal rod and lower the seed crystal from the top of the crystal growth furnace. Remelt in the mixed melt, keep the temperature for 30 minutes, and quickly cool down to the saturation temperature of 615°C;

Slowly lower the temperature at a rate of 3°C/day, rotate the seed crucible at a speed of 5 rpm, lift the crystal from the surface of the melt after the crystal grows to the desired size, and lower it to room temperature at a rate of 1°C/h, then The crystal is taken out from the furnace to obtain a Ba ₃ B ₆ O ₁₁ F ₂ crystal with a size of 25mm×24mm×10mm.

The raw material barium bicarbonate in the reaction formula can be replaced by barium carbonate or barium nitrate or barium oxalate or barium hydroxide or barium oxide, and boric acid can be replaced by boron oxide.

Embodiment 6:

According to the reaction formula: 2BaCO ₃ +BaF ₂ +3B ₂ O ₃ →Ba ₃ B ₆ O ₁₁ F ₂ +2CO ₂ ↑synthesis of Ba ₃ B ₆ O ₁₁ F ₂ compound:

Weigh BaCO ₃ , BaF ₂ , B ₂ O ₃ raw materials directly in a molar ratio of 2:1:3, and mix the weighed raw materials with flux H ₃ BO ₃ -PbO in a molar ratio of 1:6, wherein H ₃ The molar ratio of BO ₃ to PbO is 3:1, put it into a Φ80mm×80mm open platinum crucible, raise the temperature to 650°C, keep the temperature for 80 hours to obtain a mixed melt, and then lower the temperature to 615°C;

Slowly cool down to room temperature at a rate of 5°C/h, and spontaneously crystallize to obtain barium fluoroborate seed crystals;

Fix the obtained Ba ₃ B ₆ O ₁₁ F ₂ seed crystal on the seed crystal rod and lower the seed crystal from the top of the crystal growth furnace. Melt back in the mixed melt, keep the temperature for 5 minutes, and quickly cool down to the saturation temperature of 610°C;

Then slowly lower the temperature at a rate of 3°C/day, and rotate the seed rod at a speed of 15 rpm. After the crystal grows to the desired size, remove the crystal body from the surface of the melt and drop it to room temperature at a rate of 15°C/h, and then The crystal is taken out from the furnace to obtain a Ba ₃ B ₆ O ₁₁ F ₂ crystal with a size of 35mm×25mm×20mm.

The raw material barium oxide in the reaction formula can be replaced by barium carbonate or barium nitrate or barium oxalate or barium hydroxide or barium bicarbonate, and boron oxide can be replaced by boric acid.

Example 7

According to the reaction formula: 2Ba(NO ₃ ) ₂ +BaF ₂ +3B ₂ O ₃ →Ba ₃ B ₆ O ₁₁ F ₂ +4NO ₂ ↑+O ₂ ↑ to synthesize the Ba ₃ B ₆ O ₁₁ F ₂ compound;

Ba(NO ₃ ) ₂ , BaF ₂ , B ₂ O ₃ are directly weighed raw materials in a molar ratio of 2:1:3, and mixed with flux NaF-PbO in a molar ratio of 1:2, wherein The molar ratio of NaF to PbO is 3:2, put it into an open platinum crucible of Φ80mm×80mm, raise the temperature to 760°C, keep the temperature at constant temperature for 80 hours to obtain a mixed melt, and then lower the temperature to 710°C;

Slowly cool down to room temperature at a rate of 10°C/h, and spontaneously crystallize to obtain barium fluoroborate seed crystals;

Fix the obtained seed crystal on the seed rod and lower the seed crystal from the top of the crystal growth furnace, first preheat the seed crystal on the surface of the mixed melt for 25 minutes, and partially immerse it under the liquid surface, so that the seed crystal can be refluxed in the mixed melt. Melt, keep the temperature for 25 minutes, and quickly cool down to the saturation temperature of 700°C;

Then lower the temperature at a rate of 5°C/day, and rotate the seed rod at a speed of 30rpm. After the crystal grows to the desired size, lift the crystal from the surface of the melt, and lower it to room temperature at a rate of 35°C/h, and then The crystal is taken out from the furnace to obtain a Ba ₃ B ₆ O ₁₁ F ₂ crystal with a size of 22mm×32mm×20mm.

The raw material barium nitrate in the reaction formula can be replaced by barium bicarbonate or barium carbonate or barium oxalate or barium hydroxide or barium oxide, and boron oxide can be replaced by boric acid.

Example 8

According to the reaction formula: 2BaO+BaF ₂ +3B ₂ O ₃ →Ba ₃ B ₆ O ₁₁ F ₂ to synthesize the Ba ₃ B ₆ O ₁₁ F ₂ compound;

Put BaO, BaF ₂ , B ₂ O ₃ into a mortar at a molar ratio of 2:1:3, mix and grind carefully, then put it into a corundum crucible with an opening of Φ100mm×100mm, press it tightly, and put it into a muffle In the furnace, slowly heat up to a temperature of 550°C and keep the temperature constant for 24 hours. After cooling, take out the crucible. At this time, the sample is relatively loose. Then take out the sample and re-grind it evenly, and then put it in the crucible. After 48 hours, take it out, put it into a mortar _, crush _and grind it to get the Ba ₃ B ₆ O ₁₁ F ₂ compound, and carry out X-ray analysis on the product _. The X-ray spectra obtained from the F ₂ single crystal structure are consistent;

Then mix the synthesized Ba ₃ B ₆ O ₁₁ F ₂ compound with the flux Na ₂ O-PbO in a molar ratio of 1:4, wherein the molar ratio of Na ₂ O to PbO is 2:2, and put it into Φ80mm×80mm In an open platinum crucible, the temperature was raised to 770°C, and the temperature was kept constant for 70 hours to obtain a mixed melt, and then lowered to a temperature of 725°C;

Slowly cool down to room temperature at a rate of 4.0°C/h, and spontaneously crystallize to obtain barium fluoroborate seed crystals;

Fix the obtained Ba ₃ B ₆ O ₁₁ F ₂ seed crystal on the seed crystal rod and lower the seed crystal from the top of the crystal growth furnace, preheat the seed crystal on the surface of the mixed melt for 8 minutes, and immerse it under the liquid surface to make the seed crystal Remelt in the mixed melt, keep the temperature for 8 minutes, and quickly cool down to the saturation temperature of 720°C;

Slowly lower the temperature at a rate of 0.8°C/day, and rotate the seed crucible at a speed of 10rpm. After the crystal grows to the desired size, remove the crystal body from the surface of the melt and drop it to room temperature at a rate of 5°C/h, and then The crystal is taken out from the furnace to obtain a Ba ₃ B ₆ O ₁₁ F ₂ crystal with a size of 18mm×22mm×15mm.

The raw material barium oxide in the reaction formula can be replaced by barium carbonate or barium bicarbonate or barium oxalate or barium hydroxide or barium nitrate, and boron oxide can be replaced by boric acid.

Example 9

According to the reaction formula: 2Ba(OH) ₂ +BaF ₂ +3B ₂ O ₃ →Ba ₃ B ₆ O ₁₁ F ₂ +2H ₂ O↑ to synthesize the Ba ₃ B ₆ O ₁₁ F ₂ compound:

Put Ba(OH) ₂ , BaF ₂ , B ₂ O ₃ into a mortar at a molar ratio of 2:1:3, mix and grind carefully, then put it into a Φ100mm×100mm open corundum crucible, and press it tightly. Put it into a muffle furnace, slowly raise the temperature to 550°C, and keep the temperature constant for 24 hours. After cooling, take out the crucible. At this time, the sample is relatively loose. Then take out the sample and re-grind it evenly. Then put it in the crucible. 780°C and constant temperature for 48 hours, take it out, put it in a mortar, mash and grind it to get the Ba ₃ B ₆ O ₁₁ F ₂ compound, carry out X-ray analysis on the product, the obtained X-ray spectrum is consistent with that of barium fluoroborate Ba ₃ The X-ray spectra obtained from the B ₆ O ₁₁ F ₂ single crystal structure are consistent;

Then mix the synthesized Ba ₃ B ₆ O ₁₁ F ₂ compound with the flux H ₃ BO ₃ -PbO in a molar ratio of 1:4, the molar ratio of H ₃ BO to PbO is 2:1, and put it into Φ80mm×80mm In an open platinum crucible, the temperature was raised to 630°C, and the temperature was kept constant for 45 hours to obtain a mixed melt, and then lowered to a temperature of 620°C;

Slowly cool down to room temperature at a rate of 6.5°C/h, and spontaneously crystallize to obtain barium fluoroborate seed crystals;

Fix the obtained Ba ₃ B ₆ O ₁₁ F ₂ seed crystal on the seed crystal rod and lower the seed crystal from the top of the crystal growth furnace. Melt back in the mixed melt, keep the temperature for 15 minutes, and quickly cool down to the saturation temperature of 615°C;

Slowly lower the temperature at a rate of 2°C/day, and rotate the seed rod at a speed of 60rpm. After the crystal grows to the desired size, remove the crystal body from the surface of the melt and drop it to room temperature at a rate of 80°C/h, and then The crystal is taken out from the furnace to obtain a Ba ₃ B ₆ O ₁₁ F ₂ crystal with a size of 24mm×22mm×15mm.

The raw material barium hydroxide in the reaction formula can be replaced by barium carbonate or barium bicarbonate or barium oxalate or barium nitrate or barium oxide, and boron oxide can be replaced by boric acid.

Example 10

According to the reaction formula: 2Ba(HCO ₃ ) ₂ +BaF ₂ +3B ₂ O ₃ →Ba ₃ B ₆ O ₁₁ F ₂ +4CO ₂ ↑+2H ₂ O↑ to synthesize the Ba ₃ B ₆ O ₁₁ F ₂ compound:

Put Ba(HCO ₃ ) ₂ , BaF ₂ , B ₂ O ₃ into a mortar at a molar ratio of 2:1:3, mix and grind carefully, then put it into a corundum crucible with an opening of Φ100mm×100mm, and press it tightly , put it into the muffle furnace, slowly raise the temperature to 550°C, and keep the temperature constant for 24 hours. After cooling, take out the crucible. At this time, the sample is relatively loose. Then take out the sample and grind it evenly, then put it in the crucible, and place it in the muffle furnace at The temperature is 780°C and the temperature is kept constant for 48 hours. Take it out, put it into a mortar, mash and grind it to get the Ba ₃ B ₆ O ₁₁ F ₂ compound. The X-ray analysis of the product shows that the obtained X-ray spectrum is consistent with that of barium fluoroborate Ba The X-ray spectra obtained from the single crystal structure of ₃ B ₆ O ₁₁ F ₂ are consistent;

Mix the synthesized Ba ₃ B ₆ O ₁₁ F ₂ compound with the flux NaF-PbO in a molar ratio of 3:2, wherein the molar ratio of NaF to PbO is 2:1, and put it into a Φ80mm×80mm open platinum crucible, Raise the temperature to 900°C, keep the temperature for 5 hours to obtain a mixed melt, and then lower the temperature to 750°C;

Slowly cool down to room temperature at a rate of 4.0°C/h, and spontaneously crystallize to obtain barium fluoroborate seed crystals;

Fix the obtained Ba ₃ B ₆ O ₁₁ F ₂ seed crystal on the seed crystal rod and lower the seed crystal from the top of the crystal growth furnace. Melt back in the mixed melt, keep the temperature for 25 minutes, and quickly cool down to the saturation temperature of 745°C;

Then lower the temperature at a rate of 3°C/day, and rotate the seed rod at a speed of 50rpm. After the crystal grows to the required size, the crystal body is separated from the surface of the melt, and the temperature is lowered to room temperature at a rate of 70°C/h, and then the The crystal is taken out from the furnace to obtain a Ba ₃ B ₆ O ₁₁ F ₂ crystal with a size of 22mm×21mm×16mm.

The raw material barium bicarbonate in the reaction formula can be replaced by barium carbonate or barium hydroxide or barium oxalate or barium nitrate or barium oxide, and boron oxide can be replaced by boric acid;

Example 11

According to the reaction formula: 2BaC ₂ O ₄ +BaF ₂ +3B ₂ O ₃ →Ba ₃ B ₆ O ₁₁ F ₂ +2CO ₂ ↑+2CO to synthesize Ba ₃ B ₆ O ₁₁ F ₂ compound:

Put BaC ₂ O ₄ , BaF ₂ , B ₂ O ₃ in a mortar with a molar ratio of 2:1:3, mix and grind carefully, then put it into a corundum crucible with an opening of Φ100mm×100mm, press it tightly, and put Put it into the muffle furnace, slowly raise the temperature to 550 ° C, keep the temperature for 24 hours, take out the crucible after cooling, at this time the sample is relatively loose, then take out the sample and grind it evenly, then put it in the crucible, in the muffle furnace at a temperature of 780 ℃ and constant temperature for 48 hours, take it out, put it into a mortar, mash and grind it to get the Ba ₃ B ₆ O ₁₁ F ₂ compound, carry out X-ray analysis on the product, the obtained X-ray spectrum is consistent with the barium fluoroborate Ba ₃ B The X-ray spectra obtained from the single crystal structure of ₆ O ₁₁ F ₂ are consistent;

Mix the synthesized Ba ₃ B ₆ O ₁₁ F ₂ compound with the flux H ₃ BO ₃ -PbO in a molar ratio of 1:3, wherein the molar ratio of H ₃ BO ₃ to PbO is 5:1, and put it into Φ80mm×80mm In the open platinum crucible, the temperature was raised to 800°C, and the temperature was kept constant for 50 hours to obtain a mixed melt, and then the temperature was lowered to 720°C;

Slowly cool down to room temperature at a rate of 4.0°C/h, and spontaneously crystallize to obtain barium fluoroborate seed crystals;

Fix the obtained Ba ₃ B ₆ O ₁₁ F ₂ seed crystal on the seed crystal rod and lower the seed crystal from the top of the crystal growth furnace. Remelt in the mixed melt, keep the temperature for 25 minutes, and cool down to the saturation temperature of 715°C;

Then lower the temperature at a rate of 2°C/day, and rotate the seed rod at a speed of 28rpm. After the crystal grows to the desired size, the crystal body is separated from the surface of the melt, and the temperature is lowered to room temperature at a rate of 25°C/h, and then the The crystal is taken out from the furnace to obtain a Ba ₃ B ₆ O ₁₁ F ₂ crystal with a size of 30mm×22mm×15mm.

The raw material barium oxalate in the reaction formula can be replaced by barium carbonate or barium hydroxide or barium bicarbonate or barium nitrate or barium oxide, and boron oxide can be replaced by boric acid;

Example 12

Process any Ba ₃ B ₆ O ₁₁ F ₂ crystal obtained in Examples 1-11 into a frequency doubling device with a size of 5mm×5mm×6mm according to the matching direction, place it at position 3 as shown in Figure 2, and place it at room temperature Next, a Q-switched Nd:YAG laser is used as the light source, and the incident wavelength is 1064nm. The infrared beam 2 emitted by the Q-switched Nd:YAG laser 1 with a wavelength of 1064nm is injected into the Ba ₃ B ₆ O ₁₁ F ₂ single crystal 3, and the resulting wavelength is 532nm. Green frequency-doubled light, the output intensity is 5 times that of KDP under the same conditions, and the outgoing beam 4 contains infrared light with a wavelength of 1064nm and green light with a wavelength of 532nm, which is filtered by the filter 5 to obtain a green laser with a wavelength of 532nm.

Claims (4)

1. a compound barium fluoborate non-linear optic crystal, is characterized in that the chemical formula of this crystal is Ba ₃b ₆o ₁₁f ₂, do not have symmetry centre, belong to oblique system, spacer P2 (1), unit cell parameters is β=101.351 (4) °, Z=2, molecular weight 690.88.

2. the preparation method of compound barium fluoborate non-linear optic crystal according to claim 1, it is characterized in that adopting solid reaction process synthetic compound and high temperature solution method growth barium fluoborate non-linear optic crystal, concrete operations follow these steps to carry out:

A, by barium fluoborate compound single-phase polycrystal powder and fusing assistant Homogeneous phase mixing, temperature 650-900 DEG C is heated to the temperature rise rate of temperature 1-30 DEG C/h, constant temperature 5-80 hour, obtain mixed molten liquid, be cooled to temperature 610-830 DEG C again, wherein the mol ratio of barium fluoborate compound single-phase polycrystal powder and fusing assistant is 1: 1-6, and described fusing assistant is NaF-H ₃bO ₃, H ₃bO ₃-Na ₂o, Na ₂o-PbO, LiF-PbO, NaF-PbO or H ₃bO ₃-PbO;

Or be directly barium carbonate, nitrate of baryta, barium oxide, hydrated barta, barium bicarbonate or barium oxalate by containing barium compound, barium fluoride and boric acid and fusing assistant are NaF-H ₃bO ₃, H ₃bO ₃-Na ₂o, Na ₂o-PbO, LiF-PbO, NaF-PbO or H ₃bO ₃-PbO mixes, be heated to temperature 650-900 DEG C with the temperature rise rate of temperature 1-30 DEG C/h, constant temperature 5-80 hour, obtains mixed molten liquid, be cooled to temperature 610-830 DEG C again, wherein the mol ratio of containing barium compound, barium fluoride and boric acid and fusing assistant is 2: 1: 6: 1-6;

B, prepare barium fluoborate seed crystal: the mixed molten liquid obtained by step a is slowly down to room temperature with the speed of temperature 0.5-10 DEG C/h, spontaneous crystallization obtains barium fluoborate seed crystal;

C. the crucible filling the mixed molten liquid that step a obtains is inserted in crystal growing furnace, the seed crystal obtained by step b is fixed on seed rod, seed crystal from crystal growing furnace top, first preheating seed crystal 5-60 minute, seed crystal is carried out melt back in contact mixed molten liquid liquid level or mixed molten liquid, constant temperature 5-60 minute, is down to temperature of saturation with the speed of temperature 1-60 DEG C/h;

D, again with the speed slow cooling of temperature 0.1-5 DEG C/day, the growth of crystal is carried out with 0-60rpm rotating speed rotary seed crystal rod, arrive after required yardstick until single crystal growing, by crystal lift-off mixed molten liquid surface, and be down to room temperature with temperature 1-80 DEG C/h speed, then crystal is taken out from burner hearth, barium fluoborate non-linear optic crystal can be obtained.

3. method according to claim 2, is characterized in that fusing assistant NaF-H ₃bO ₃naF and H in system ₃bO ₃mol ratio be 1-5: 3-6; In LiF-PbO or NaF-PbO system, the mol ratio of fluorochemical and plumbous oxide is 1-5: 1-6; H ₃bO ₃-PbO or H ₃bO ₃-Na ₂the mol ratio of O system mesoboric acid and oxide compound is 2-5: 1-5; Na ₂in O-PbO system, the mol ratio of sodium oxide and plumbous oxide is 1-5: 0.1-6.

4. the purposes of barium fluoborate non-linear optic crystal according to claim 1 in preparation times frequency generator, upper frequency transmodulator, lower frequency transmodulator or optical parametric oscillator.