JPS6287493A - Production of ruby single crystal - Google Patents

Abstract

PURPOSE:To obtain a single crystal without inclusion or endomorph of crystallites, by using a compound selected from Li salt, Na and K molybdates and MoO3 as a flux in producing a ruby single crystal by a flux method. CONSTITUTION:One or two or more selected from lithium molybdate, sodium molybdate, potassium molybdate and molybdenum trioxide are used as a flux, put in a crucible and melted while heating. Al2O3 and 1-10wt%, based on the Al2O3, Cr2O3 as a colorant are then added and dissolved in the melt and further a growth ruby seed piece is added and annealed to grow the aimed ruby single crystal. As a result, the ruby single crystal of good quality without inclusion or endomorph of crystallites and uneven color is obtained. The use of the above-mentioned flux eliminates evaporation of the flux and facilitates the flux control.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for producing a ruby single crystal with an improved flux component, in which a flux component selected from lithium molybdate, sodium molybdate, potassium molybdate, and molybdenum trioxide is used. By using one or more of these as a solvent, the quality of the single crystal obtained can be greatly improved.

[Conventional technology]

Conventionally, ruby single crystals produced by the flux method have been prepared, for example, in the literature (K, NASSAV" () eme Madeby
As shown in Man'p, 75-p, 83), PbF2, PbO, PbO-B2O, etc. were used as solvents.

[Problems and objects to be solved by the invention] However, these solvents volatilize rapidly and it is very difficult to maintain a constant composition. For example, when a single crystal is grown using these solvents, the volume of the solvent decreases by 60% by the time the growth is completed. That is, the supply of raw materials to the crystal to be grown becomes unstable, and the quality of the crystal is greatly reduced, such as inclusions and microcrystals being included in the resulting crystal. In particular, when crystals are used as gemstones, inclusions are the biggest cause of decreased transparency, which is a fatal drawback for gemstones.The present invention solves the above problems, and its purpose is to The object of the present invention is to provide a method for producing a very high quality ruby single crystal that does not contain defects such as crystals or microcrystals.

[Means for solving problems]

The method for producing a ruby single crystal of the present invention is characterized in that one or more selected from lithium molybdate, sodium molybdate, potassium molybdate, and molybdenum trioxide are used as a solvent.〇The present invention The solvent is stable in the crystal growth temperature range, hardly evaporates, and can keep the composition constant for a long period of time. Because it is stably supplied, crystals free of defects such as inclusions, microcrystals, and color unevenness can be obtained.

In addition, the amount of Or, OB added as a coloring agent is preferably within the range mentioned above, since if the weight ratio of A fi, O is less than 1%, the color tone will be lighter than that of a ruby, and if it exceeds 10%, it will be too dark. , more preferably in the range of 2 to 5%.

〔Example〕

[Example 1] Example 1 will be described below.

Liz Mo as a solvent (hereinafter referred to as flux)
A mixture of 04 and M2O3 at a weight ratio of 1:1 was used in 19, and this flux was melted at 900° C. in a platinum crucible and crucible furnace. Add A fi20° to this
51 was added and dissolved. Three days later, A II! When the dissolved amount of 203 was analyzed using an emission spectrometer, it was found that 90% of the saturated dissolved amount was dissolved. Next, Or2 as a colorant
03 to 0.45 S' (A fi, O in weight ratio.

30%) was added and dissolved.

After 2 days, ruby seed crystal pieces for cultivation were added, and 4 seeds per day were added.
It was slowly cooled to 150°C at a slow cooling rate of 150°C to grow a ruby single crystal.

Examining the obtained crystals, the amount of growth was 30 per day on one side.
It was μ. In addition, no inclusions or microcrystals were observed at all, and a beautiful ruby single crystal of extremely high quality with no uneven color was obtained.

In addition, as a comparative example, crystals were grown under the above conditions by changing only the amount of Or, o, added so that it was outside the above range, but the color tone was too pale or too dark to be called ruby. It wasn't practical.

[Example 2] Example 2 will be explained below@ As a flux, a mixture of Na2MoO and M2O3 in a weight ratio of 1=1 was used. was dissolved at 900°C. 201 of A fi, 03 was added to this and dissolved. After 3 days, A℃, 0. When the dissolved amount was analyzed using an emission spectrometer, it was found that 80% of the saturated dissolved amount was dissolved. Next, CJr and OB as colorants were dissolved in 082 (4.0% of A L O, by weight ratio). ) added and dissolved.

After 2 days, ruby seed crystal pieces for growth were added, and 3 seeds per day were added.
Examination of the crystals obtained by slow cooling to 150° C. revealed that the growth rate was 20 μm per day on one side. Also,
No inclusions or microcrystalline inclusions were observed.
A beautiful ruby single crystal of extremely high quality with no color unevenness was obtained. [Effects of the invention] As described above, according to the present invention, lithium molybdate, sodium molybdate, potassium molybdate, molybdenum trioxide, etc. By using one or more selected from as a solvent, inclusion microcrystals can be obtained in the crystal. In particular, it has great practical effects when applied to products where quality is an important factor, such as synthetic gemstones and functional crystals for lasers and masers. In addition, since the solvent evaporates less and the composition is stable, the solvent can be easily managed, which has great effects in improving mass productivity and safety.

that's all

Claims (2)

[Claims] (1) A manufacturing method for growing a ruby single crystal by a flux method, characterized in that one or more selected from lithium molybdate, sodium molybdate, potassium molybdate, and molybdenum trioxide are used as a solvent. A method for producing a ruby single crystal. (2) Chromium oxide (Or_2O_3) as a coloring agent is mixed with aluminum oxide (Al_2O_3), which is a ruby component by weight.
The method for producing a ruby single crystal according to claim 1, in which 1 to 10% of ruby is added to 2O_3).