| 摘要 |
PURPOSE:A starting bar made of Al2O3, TiO, BeO and Fe3O4 and chrysoberyl crystals are used to effect the growth of crystals by the floating zone method, then TiO is precipitated to give the chrysoberyl crystals clear cat's eye effect. CONSTITUTION:Al2O3-TiO 1:1 solid solution is combined with BeO and Fe2O3 to prepare a starting powder having the constitution of naturally occurring chrysoberyl cat's eye. The powder is charged in a rubber tube, deaerated and formed into a cylindrical bar by the rubber press method. The resultant bar and a sintered chrysoberyl starting material or chrysoberyl crystals as seeds are used to effect the growth of crystals by the floating zone method. Then, the resultant crystals are annealed at 1,000-1,500 deg.C in an oxidative atmosphere to precipitate TiO. The direction of TiO crystal precipitation is the same as that of crystal growth. The resultant single crystal is cut and ground to give a chrysoberyl crystal with clear cat's eye effect. |
