Preparation of YBa₂Cu₃O_{7 − δ} Thin Films by the Self-Template Sputtering Method

Abstract

Using the self-template technique, c-axis-oriented epitaxial YBa₂Cu₃O_{7 − δ} thin films have been prepared in situ on LaAlO₃ substrate by the d.c. magnetron sputtering method. The properties of thin film dependence on the deposition conditions of the two-step self-template method have been systematically investigated. By optimizing the parameters, high-quality YBCO thin films with T _c0 ≥ 90 K, ΔT _c ≤ 1 K, R _s (77 K, 10 GHz)∼500 μΩ were reproducibly obtained. The best sample grown under optimal conditions gave a low R _s of 330 μΩ at 77 K, 10 GHz, which can be used in a microwave field.