Metalorganic chemical vapor deposition of Tl2CaBa2Cu2Oy superconducting thin films on sapphire.

Superconducting Tl2CaBa2Cu2Oy thin films have been successfully grown on the single-crystal sapphire (1102) substrate by using the metalorganic chemical vapor deposition technique. The growth rate of the films was about 5 μm/h. The as-deposited film was post-annealed in a partially sealed ceramic crucible in the presence of a Tl2Ca2Ba2Cu3Oy pellet to achieve the superconducting phase. The x-ray data show strong diffraction from the Tl2CaBa2Cu2Oy superconducting phase in addition to the trace amounts of Ca2CuO3 and BaCO3. Superconducting transition temperatures with onset above 100 K and zero resistance at 94 K can be obtained by further heat treatment at 500 °C in oxygen. [ABSTRACT FROM AUTHOR]