Microstructure and microwave loss studies on epitaxial YBa2Cu3Ox thin films
Thin YBa2Cu3Ox films were grown on SrTiO3 or LaAlO3 single crystals by dc-magnetron reactive sputtering in argon/oxygen gas mixtures. Deposition temperatures ranged from 540 °C to 780 °C. After deposition and subsequent cool down, films grown above 680 °C are superconducting below 86–88 K. All films are oriented with the [001] direction parallel to the [001] substrate normal. The best films have c