| 摘要 |
PURPOSE:To obtain the title high-quality single crystal by detecting the weight of a growing crystal, setting the rate of change of a high-frequency electric power at a specified value when the crystal weight is in any of the plural relational regions calculated based on the desired weight to control the diameter with good reproducibility. CONSTITUTION:For example, the Nd:YAG single crystal material 2, obtained by doping high-purity Al2O3 and Y2O3 with 0.8at% Nd, weighing the appropriate amts. of both materials, and mixing the materials, is charged in the Ir crucible 1 of a single crystal growth device, an electric power is impressed under the command of a personal computer 5 on a high-frequency coil 3 through a D/A conversion circuit 7, an analog controller 8, and a high-frequency oscillator 9 to melt the material, and pulling up is started. The equations I-V (0<=l<=0.01, 0.01<=m<=0.05, and n>=0.05) are calculated with use of the signal 4 from a load cell and the signal 10 from a vacuum thermocouple based on the desired weight Wx. When the crystal weight Wi is in any of the regions of the equations I-V, the rate V0 of change of the high-frequency power is set at equation VI (V01 is the rate of change of the high-frequency power immediately before the growth, alpha is 0-1 in case of a, 1-0.5 in case of b, 1.5-2 in case of c, 0.5-1.0 in case of d, and -0.5-0.5 in case of e), and the crystal is grown.
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