| abstract |
PURPOSE:To uniformly color an alumina single crystal body and provide high value as a precious stone by forming a thin film contg. zirconium oxide and a metal oxide on the body surface by sputtering after which the crystal body covered with the film is buried in mixed powder of zirconium and a metal oxide, and heat treated. CONSTITUTION:A thin film contg. zirconium oxide and a metal oxide such as cobalt or chromium oxide as a colorant is formed on the surface of an elumina single crystal body by sputtering, pref. high frequency sputtering. The crystal body may be a natural body such as ruby or sapphire, or an artificial body produced by Verneuil method. The ratio of the zirconium oxide and metal oxide in the film is pref. 1-10:10 by wt., and the thickness of the film is 0.1-10, pref. 0.5-3mu. The crystal body covered with the film is then buried in mixed powder of (A) zirconium oxide or carbonate and (B) a metal oxide or carbonate, and heat treated at 1000-1500 deg.C to be colored. The mixing ratio of the component A and B is 1- 450:1, pref. 1-400:1. |