Effect of the laser sputtering parameters on the orientation of a cerium oxide buffer layer on sapphire and the properties of a YBa2Cu3Ox superconducting film

The effect of the laser sputtering parameters on the crystal properties of CeO2 buffer layers grown on a (1 (1) under bar 02) sapphire substrate and o n the properties of superconducting YBa2Cu3Ox thin films are investigated. It is shown that (100) and (111) CeO2 growth is observed, depending on the sputtering conditions. A buffer layer with the desired unidirectional orien tation can be obtained by varying the heater temperature, the pressure in t he chamber, and the energy density of the laser beam at the target. (C) 199 9 American Institute of Physics.