Superconducting YBa2Cu3Ox Thin Film Growth on a Vicinal Surface of NdGaO3 Substrate

Surface morphology is observed for a superconducting YBa2Cu3Ox (YBCO) thin film grown on a 1.7° off angle vicinal surface of lattice-matched NdGaO3 substrate. Ragged step-like edges are clearly observable with exclusions in the front of the edges. The height of a step is measured to be 20 A~30 A and is calculated from the vicinal angel and the terrace width to be 23±2 A, indicating an evidence for a doubled periodicity of YBCO crystal c-axis unit length of ~12 A.