Phase development and crystallization of CuAlO2 thin films prepared by pulsed laser deposition

A polycrystalline CuAlO2 single-phase target was fabricated by the conventional solid-state reaction route using Cu2O and Al2O3. Thin films of CuAlO2 were deposited by a pulsed laser deposition process on sapphire substrates at different temperatures. Then, post-annealing was followed at different conditions, and the phase development process of the films was examined. As grown thin films in the temperature range of 450-650 degrees C were amorphous. The c-axis oriented single phase of CuAlO2 thin films were obtained when the films were post-annealed at 1100 degrees C in air after growing at 650 degrees C. Phi-scan of the film clearly showed 12 peaks, each of which are positioned at intervals of 30 degrees. This is thought to be caused by the rhombohedral structured CuAlO2 thin film growing in the states of 30 degrees tilt during the annealing process. Hall effect analysis of the film was carried out. (C) 2009 Elsevier Ltd. All rights reserved.