Superconducting YBa2Cu3Ox films prepared by rf plasma flash evaporation

Abstract

Superconducting YBa2Cu3Ox films were prepared by rf plasma flash evaporation on MgO(100) single crystals. 4 MHz rf Ar–O2 plasma was used and Y–Ba–Cu–O (YBCO) powder as raw material was fed into the plasma. The growth rate of 730 nm/min was achieved. Texture of the grown films varied from a-axis orientation to c-axis with increasing growth temperature and decreasing growth rate. The films without heat treatment exhibited zero resistance temperature (Tc0) more than 77 K. The deposited films using the stoichiometric powder were slightly poor in Y. The sample using Y-rich powder revealed nearly stoichiometric composition and exhibited a Tc0 of 90.6 K and a critical current density (Jc) of 6.8 × 105 A/cm2 at 77 K in zero applied field.