Manipulation of YBCO film properties by the introduction of perovskite BaTiO3 nanodots as substrate decorations

Perovskite BaTiO3 (BTO) nanodots were deposited on LaAlO3 (LAO) substrates using the BTO precursor solutions with various low concentrations. Subsequently, YBa2Cu3O7-x (YBCO) superconducting films were deposited on the BTO-dots decorated LAO substrates through a low-fluorine solution method. High BTO dots (with heights of 30-50 nm) and short BTO nanodots (with heights less than 30 nm) were produced using a solution with a concentration of 0.025 mol/L, which could not be produced using solutions of other concentrations. We found a significantly enhanced flux pining force in the YBCO film deposited on the BTO-dots decorated LAO substrate. Because of the joint pinning effect of the high BTO dots and short BTO dots, the high-performance YBCO film with a critical current density of 8.42 MA/cm2 and a flux pinning force of 9.58 GN/m3 was produced on the LAO substrate.