High-quality YBa2Cu3O7-δ thin films grown on SrLaAlO4(001) and (1118) substrates

SrLaAlO4 (SLAO) was used as a substrate for the epitaxial growth of YBa2Cu3O7-δ (YBCO) thin films. This material has dielectric properties comparable to those of the commonly used LaALO3 substrate. The lattice mismatch between SLAO (001) and YBCO (001) is about 3%. Two substrate orientations, cleaved (001) and polished (1118), have been used in this study. YBCO thin films were grown epitaxially from both orientations by in situ laser ablation. The stepped morphology of the cleaved SLAO (001) surface promoted the growth of YBCO along the a-axis. In the case of the SLAO (1118), YBCO (1118) was grown with its c-axis aligned along the c-axis of SLAO. The YBCO (1118) has a Tc of over 90 K with a transition width of 0.5 K, which indicates a high-quality superconductor.