Published online by Cambridge University Press: 10 February 2011
Ferro-electric (BSTO) films of 1 μm nominal thickness were deposited on single crystals of sapphire at substrate temperatures varying from 30 °C to 700 °C. Optical analysis showed that the thin films were amorphous up to 500 °C, while at 700 °C they were polycrystalline. The microstructure of the thin films was columnar at all substrate temperatures. The film microhardness increased with increasing substrate temperature. While the cohesion failure load of the films remained fairly constant, the adhesion failure load increased with increasing substrate temperature.