Effect of Substrate Temperature and Composition on the Crystalline State of Ba₂YCu₃O7-δ Magnetron-Sputtered Thin Films

The effect of substrate temperature and composition on the crystalline state of Ba 2 YCu 3 O 7-δ thin films prepared by magnetron sputtering are investigated. The as-sputtered films deposited above 560°C have a c-axis orientation perpendicular to the substrate. Their superconducting transition temperature are above 80 K at the thickness of 4000 Å and 48 K at the thickness of 100 Å. The preferred orientation and superconducting properties are strongly affected by the amount of deviation from the stoichiometric composition.