YBCO thin films on TiO/sub 2/ buffer layer deposited by RF magnetron sputtering

Rutile structure TiO/sub 2/ buffer layers and YBa/sub 2/Cu/sub 3/O/sub 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 TiO/sub 2/ buffer layers. The crystal structure of TiO/sub 2/ thin films changed from (100) oriented anatase structure TiO/sub 2/ to [110] oriented rutile structure TiO/sub 2/ with increasing substrate temperature. The [110] oriented rutile structure TiO/sub 2/ thin films deposited with the optimal deposition condition had smooth surfaces. YBCO thin films on [110] oriented rutile structure TiO/sub 2/ buffer layers had better crystallinity and surface flatness than YBCO thin films deposited on bare MgO substrates.