JPH0293290A - Ferrite melting crucible - Google Patents

Abstract

PURPOSE:To obtain highly pure single crystal of ferrite by disposing a straight tubular nozzle which vertically extends both inwardly and outwardly to penetrate the center of the bottom of a crucible, and allowing only the molten ferrite to stream down to be collected in a single crystal forming crucible. CONSTITUTION:When ferrite 2 is melted in a ferrite melting pot 6, platinum will melt primarily from its wall into the molten ferrite 2. Since the platinum grains 4 have a specific gravity greater than that of ferrite, they drop and settle on the flat bottom of the pot 6. Because a tubular nozzle 7 extends vertically inwardly through the center of the bottom of the pot 6, the platinum grains 4 will not enter into the tubular nozzle 7, and so, only the molten ferrite 2 streams down to be collected in a single crystal forming crucible 1. Therefore, highly pure single crystal of ferrite can be obtained in the single crystal forming crucible 1.

Description

[Detailed description of the invention] (Field of use in M industry) The present invention relates to improvements in ferrite melting crucibles.

(Prior art) Conventionally, in order to grow a ferrite single crystal, ferrite 2 is placed in a cylindrical single crystal growth crucible 1 made of platinum shown in FIG. 4, and the entire crucible 1 is heated for a long time (50 to 100 hours). 1
The temperature was maintained at 600 to 1700°C to grow ferrite 2 into melted crystals. However, in this method, platinum is eluted into the ferrite 2, and as shown in the figure, the platinum is eluted into the ferrite single crystal 3.
The distribution of platinum grains 4 was small in the center part, but a large amount of platinum grains 4 were distributed in the outer peripheral part.

For this purpose, as shown in FIG. 5, ferrite 2 is melted in a small diameter cylindrical ferrite melting crucible 5 made of platinum, and the molten ferrite 2 is immediately introduced into a single crystal growth crucible 1 to grow a ferrite single crystal 3. was. In this method, the ferrite single crystal 3 is in a molten state in a narrow upper region. Therefore, since the melting time in the single crystal growth crucible 1 is short, platinum grains 4 are less likely to be mixed in.

(Problems to be Solved by the Invention) By the way, in the method for growing a ferrite single crystal shown in FIG. It was distributed throughout the entire crystal 3, and a highly pure ferrite single crystal could not be obtained.

Therefore, an object of the present invention is to provide a ferrite melting crucible in which, when the molten ferrite in the ferrite melting crucible flows down into a single crystal growth crucible, the platinum grains in the molten ferrite do not flow down together with the molten ferrite, but only the molten ferrite flows down. It is something to do.

(Means for Solving the Problems) The ferrite melting crucible of the present invention for solving the above problems is a cylindrical ferrite melting crucible made of platinum, and a tubular nozzle is installed inside and outside the center of the bottom of the crucible. It is characterized by being provided straight and protruding from the top.

(Function) When ferrite is melted in the ferrite melting crucible of the present invention constructed as described above, platinum is eluted mainly from the surrounding area in the melted ferrite, and since the platinum grains have a higher specific gravity than the ferrite, the crucible melts. However, since a tubular nozzle is provided in the center of the bottom of the crucible in a straight manner, protruding inward and outward, platinum grains do not flow down from the tubular nozzle, but only molten ferrite flows down. Therefore, in the crucible for single crystal growth, a highly pure ferrite single crystal can be obtained.

(Example) An example of the ferrite melting crucible of the present invention will be described with reference to FIG. 1.Inner diameter 40 mm5 depth 100+n+n
.

A cylindrical ferrite melting crucible 6 made of platinum with a wall thickness of 0.5 mm has a tubular nozzle 7 with an inner diameter of 3 mm, a length of Ll mm, and a wall thickness of Q of 5 mm in the center of the flat bottom.
It is installed straight and integrally with a protrusion of mm.

In the ferrite melting crucible 6 configured in this way, a second
When the ferrite 2 is melted as shown in the figure, platinum is eluted into the melted ferrite 2 mainly from the peripheral wall.
Since the platinum grains 4 have a higher specific gravity than the ferrite 2, they settle and accumulate on the flat bottom of the crucible 6, but a tubular nozzle 7 is installed straight in the center of the bottom of the crucible 6 with six holes protruding inward. Therefore, the platinum particles 4 do not flow down from the tubular nozzle 7, and only the molten ferrite 2 flows down into the single crystal growth crucible 1.
is filled with. Therefore, in the single crystal growth crucible 1, a highly pure ferrite single crystal can be obtained.

Although the ferrite melting crucible 6 of the above embodiment has a flat bottom, it may be of a hopper type as shown in FIG. 3A, or may be of a circular shape as shown in FIG. .

(Effects of the Invention) As can be seen from the above explanation, according to the ferrite melting crucible of the present invention, even if platinum is eluted from the peripheral wall when ferrite is melted and the platinum particles settle and accumulate on the bottom of the crucible, Since a tubular nozzle is installed straight at the center of the bottom, protruding inward and outward, platinum grains do not flow down from this tubular nozzle, and only molten ferrite flows down and fills the single crystal growth crucible, resulting in improved purity. It is possible to obtain a ferrite single crystal with high

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the ferrite melting crucible of the present invention, FIG. 2 is a longitudinal sectional view showing the state of use of the ferrite melting crucible of FIG. 1, and FIG. 3 aSb is a ferrite melting crucible of the present invention. FIGS. 4 and 5 are vertical cross-sectional views showing other embodiments of the melting crucible, and FIGS. 4 and 5 are vertical cross-sectional views showing a conventional method for growing a ferrite single crystal. Applicant: Tanaka Kikinzoku Kogyo Co., Ltd. Figure 1 Figure 2 Figure 7...Back (Q) or -2 Figure (CI) (b) Figure Figure

Claims (1)

[Claims] 1. In a cylindrical ferrite melting crucible made of platinum,
A ferrite melting crucible characterized in that a tubular nozzle is provided straight in the center of the bottom of the crucible, protruding inwardly and outwardly.