| 摘要 |
PURPOSE:To synthesize corundum free from color mottling, by the focused- light floating-zone method using a sintered raw material rod and a seed crystal composed of Al2O3, Cr2O3 and Fe2O3 having nearly the same composition as orange sapphire. CONSTITUTION:A powdery mixture of Al2O3, Cr2O3 and Fe2O3 having nearly the same composition as orange sapphire is put into a rubber tube. The tube is evacuated, and the content is pressed to a cylindrical rod by a rubber press process. The rod is sintered at about 1,300-1,600 deg.C to obtain a raw material rod 6. The rod 6 is supported by the upper main shaft 9 in a quartz tube 3 of a focused-light floating-zone synthesizing apparatus, and melted by the light emitted from halogen lamps 2 and focused by the ellipsoidal mirror 1. The process is carried out in an atmosphere gas flowing through the quartz tube 3 from the inlet 4 to the outlet 5. The molten zone 8 formed by the above process is made to contact with a seed crystal 7 such as ruby, sapphire, etc. supported by the lower main shaft to effect the growth of the corundum of an orange sapphire crystal. |
