JPS5973490A - Preparation of crystal - Google Patents

Abstract

PURPOSE:To prepare a crystal with a low-power laser beam in high efficiency, by covering the raw material of crystal with an optically transparent covering material in a spherical form, enclosing the sphere with concave mirrors provided with windows at definite intervals, and heating and melting the crystal raw material with laser beams introduced through the windows. CONSTITUTION:The raw material of crystal 1 is covered with a covering material 2 made of a transparent substance such as glass in the form of a sphere, which is enclosed with concave mirrors 6 provided with windows at definite intervals. The material 1 is heated and molten by introducing laser beams 3 through the windows 5. The radiant heat emitting from the sphere in the form of heat ray 4 by the heating of the material 1 is mostly reflected by the concave mirror 6 and focused again to the material 1. Accordingly, the radiation loss can be remarkably suppressed, and the power of the laser beam 3 can be considerably lowered by this method. After melting, the radiation of the light 3 is stopped, and the material 1 is cooled to obtain a crystal such as diamond crystal.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a crystal manufacturing method, and relates to a crystal manufacturing method, and relates to a method for manufacturing crystals using materials such as diamond, etc., which require ultra-high temperature and high pressure conditions when artificially manufacturing crystals. The present invention provides a method for manufacturing gemstones, metal crystals, etc. at low cost.

Structure and Problems of the Conventional Example In the crystal manufacturing method using an outer packaging material and a laser, which the present inventor previously proposed in Japanese Patent Application No. 57-63744,
As shown in the figure, a crystal raw material 1 is enclosed in a transparent material sphere (such as quartz or glass) that will become the outer packaging material 2, and a laser beam 3 focused from the outside is irradiated to form a core. A method has been used in which the crystal raw material 1 is mainly heated and melted, and after cooling, the outer packaging material is removed to take out the crystals, but in this method, the crystal raw material 1 is heated to a high temperature and the crystal raw material 1 is heated to a higher temperature than the crystal raw material. The amount of radiant energy emitted increases. That is, there was a drawback that energy loss was large.

For example, when manufacturing diamond, if a catalyst is not used, conditions of about 300,000 atmospheres and 30,000 degrees Celsius are required; I needed it. This means that when the temperature increases to 30,000, the thermal radiation increases to 46
This is because it also becomes 0 V'i/etl. In other words,
Most of the laser radiation was wasted as radiant heat emitted by the crystal raw material.

Purpose of the Invention In view of the drawbacks of the previously proposed methods described above, an object of the present invention is to melt the crystalline raw material with high efficiency using a low-power laser while reducing energy loss due to radiation during heating of the crystalline raw material. The purpose is to

Structure of the Invention The present invention is a method for producing an artificial crystal, in which a crystal raw material and a sphere made of an optically transparent outer envelope material surrounding the crystal raw material are in advance formed using a concave mirror provided with windows at predetermined intervals. By enclosing the crystal raw material and irradiating it with a laser beam through the window, the heat rays emitted as radiant heat from the crystal raw material heated and heated are again focused by a concave mirror and irradiated with the crystal raw material, more preferably, the concave mirror and The feature is that the temperature of the surface of the outer envelope material and the concave mirror is prevented from rising by flowing cooling gas into the gap between the outer envelope materials.

Description of examples Hereinafter, an embodiment will be described in detail using FIG. 2.

In advance, a sphere encapsulated with an outer packaging material 2 such as a transparent material such as glass so as to surround the crystal raw material 1 is wrapped with a concave mirror 6 having windows 6 at predetermined intervals, and the sillage light 3 is transmitted through the window 5. Irradiation was performed to heat and melt the crystalline raw material that served as a nucleus. At this time, as the crystal raw material 1 is heated,
Most of the radiant heat emitted as heat rays 4 to the outside of the sphere is reflected inward by the concave mirror and concentrated on the crystal raw material again. Therefore, when the method of the present invention is used, the energy emitted to the outside of the sphere is Since there is almost no loss, the power of the laser beam can be significantly reduced.When the 0-order laser beam irradiation is stopped and cooled, the raw material is removed at high temperature and high pressure, forming diamond crystals. be done. At this time, the outer packaging material hardly absorbs the heat rays, and the temperature rises mainly due to heat conduction due to contact with the heated crystal raw material, and in the case of a short time (several minutes), the outer surface The temperature did not rise very much. Also, since the concave mirror reflects most of the heat rays, the temperature did not rise much. In addition, if long-term laser irradiation is required, the surface of the outer envelope material and the concave mirror will inevitably rise in temperature, so in that case, by flowing cooling gas into the gap between the outer envelope material and the concave mirror, It was possible to prevent temperature rise.

For example, when manufacturing diamonds, conditions of about 300,000 atmospheres and 3000 degrees are required if a catalyst is not used. The entire glass powder was heated to melt and harden the glass powder serving as the outer packaging material, thereby forming a transparent glass sphere with graphite as the core inside. Alternatively, graphite may be inserted into molten glass in advance and allowed to slowly cool and harden. At this time, since the diameter of the graphite core was approximately 2 cm, the diameter of the outer envelope made of transparent glass was set to 20 cm or more.

Next, cover this sphere with a concave mirror and use the power 1 to 2 from the window.
When irradiated with KW's YAG laser, the graphite reached a temperature of over 3000'C in several tens of seconds and was melted. At this time, the outer envelope material is made of glass, which has poor thermal conductivity, and no thermal expansion occurs on the outside of the sphere for about a few minutes, resulting in the graphite being held at high temperature and high pressure. Moreover, the glass of the outer package was not damaged. This means that the graphite diameter is 2cm, while the glass diameter is 20(7) or more (
(approximately 10 times)), even if the internal pressure reaches 600,000 atm, the pressure on the glass surface will be around 6,000 atm, and the Young's modulus of the glass will be 6 to 8 x 103 Ky/crI.
Considering this, it can be seen that the glass was not destroyed. Thereafter, the laser irradiation is stopped and the sphere is cooled from the outside, and the molten crystal raw material is cooled while being held at high pressure, and as a result, a diamond crystal is obtained.

Although the present embodiment shows the laser beam 3 being irradiated from two directions, it is clear that the laser beam 3 may be irradiated from one direction or more laser beams may be irradiated from one direction.

Effects of the Invention By using the method of the present invention, it is possible to significantly reduce energy loss during the production of crystals, thereby making it possible to downsize lasers and improve energy efficiency. In addition, even if it is necessary to increase the laser irradiation time,
The surface of the outer packaging material and the concave mirror can be easily cooled.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram illustrating a crystal manufacturing method using a laser that the inventor previously proposed, and FIG. 2 illustrates a crystal manufacturing method using a windowed concave mirror according to an embodiment of the present invention. FIG. 1...Crystal raw material, 2...Outer packaging material, total...Laser, 4...Heat ray, 6...
...Window, 6...Concave mirror Name of agent Patent attorney Toshio Nakao and 1 other person No. 1 @

Claims (2)

[Claims] (1) A sphere made of a crystalline raw material and an optically transparent outer packaging material surrounding the crystalline raw material is surrounded by a concave mirror provided with windows at predetermined intervals, and a laser beam is irradiated through the window to illuminate the crystalline raw material. A crystal manufacturing method characterized by heating, melting, and cooling. (2) The crystal manufacturing method according to claim 1, characterized in that cooling gas is caused to flow through the gap between the concave mirror and the outer envelope material.