Precipitate orientation relationships in Pt-implanted sapphire

  Sapphire was implanted with Pt ions at room temperature and at liquid-nitrogen temperature, inducing correspondingly different amounts of accumulated damage in the target crystals. Subsequent thermal annealing at 1000 and at 1600 °C resulted in Pt precipitation with differing orientation relationships, associated with the degree of crystallinity of the sapphire matrix. The orientation relationships depended on whether Pt precipitated from sapphire or from a transition alumina phase that formed in partially amorphized substrates.