The growth of K-β″-Al2O3 single-crystal films on single-crystal α-Al2O3 substrates
Abstract The overgrowth of K-β″-Al 2 O 3 on single-crystal sapphire substrates has been investigated using carbonate, chloride and β″ ( β ) -Al 2 O 3 vapour sources at temperatures between 950°C and 1250°C. Single-crystal film is obtained on the sapphire substrate using a (K, Li)-β″-Al 2 O 3 powder vapour source at 1120-1250°C. The mechanism of growth and the chemical and crystallographic factors involved are discussed.