YBCO thin films on TiO2 buffer layer deposited by RF magnetron sputtering

Rutile structure TiO₂ buffer layers and YBa₂Cu₃O_7-x (YBCO) thin films have been deposited on (100) MgO substrates by RF magnetron sputtering. It was found that, high quality c-axis oriented YBCO thin films could be obtained on MgO with very thin [110] oriented rutile structure TiO₂ buffer layers. The crystal structure of TiO₂ thin films changed from (100) oriented anatase structure TiO₂ to [110] oriented rutile structure TiO₂ with increasing substrate temperature. The [110] oriented rutile structure TiO₂ thin films deposited with the optimal deposition condition had smooth surfaces. YBCO thin films on [110] oriented rutile structure TiO₂ buffer layers had better crystallinity and surface flatness than YBCO thin films deposited on bare MgO substrates.