| 摘要 |
PURPOSE:In the floating zone process using crystals of corundum as seeds, nickel oxide is used as a colorant to obtain yellow corundum called golden sapphire in low costs. CONSTITUTION:The starting substance consisting of alumina as a major constituent and nickel oxide as a colorant is charged in a rubber tube and formed into a bar by means of a rubber press. The resultant bar is sintered at 1,400-1,800 deg.C. The sintered bar is employed as the starting material and sintered corundum or crystals thereof is used as seed crystals to effect the growth of a golden sapphire crystal by means of a floating zone furnace. The amount of nickel oxide is suitably 0.2-0.3% based on the whole. |
