Systematic research on the effect of both positive and negative mismatch dopants in double-doped YBCO superconducting films

Abstract We report a novel doping strategy for YBa2Cu3O7-x (YBCO) superconducting films by using positive mismatch, Ba2YNbO6 (BYNO), and negative LaAlO3 (LAO), simultaneously. Double can significantly reduce the c-strain in YBCO film canceling strain between two dopants. By systematically optimizing amount of both BYNO LAO, it was found that LAO do not act equally. The microstructure distribution were investigated with magneto-optic microscopy scanning electron microscopy. effect on pinning confirmed. results this study will help select appropriate mismatch dopants, which is fundamental to design fabrication centers fit different application scenarios.