| 摘要 |
PURPOSE:To improve the quality of crystal and to improve the stability of growth in the synthesis of alexandrite by the floating zone process by adding oxide(s) having high melting point to a compsn. of the starting material. CONSTITUTION:A single crystal of alexandrite is grown by the floating zone process wherein an end of a starting material bar is melted, and melting of the starting material bar and deposition of solid phase are continued by moving the formed melting zone. The compsn. of the starting material bar consists primarily of alumina and beryllia, contg. additionally 0.2-0.5wt% chromium oxide and 2-4wt% ferric oxide as colorant, and adding 0.1-2wt% at least one among ZrO2, HfO2, and ThO2 as high melting oxide(s).
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