Macroscopic residual stress and properties in different YBa2Cu3O7-x heterogeneous systems

Residual stress and internal strain induced by interface lattice mismatches between YBa2Cu3O7-x thin films and substrates causes variation on microstructures and superconducting properties. In this research, we investigated small misfit misalignments of YBa2Cu3O7-x thin films prepared on (LaAlO3)O-3-(Sr2AlTaO6)(0.7) (LSAT), LaAlO3 and SrTiO3 substrates, and their resulting effects on their superconducting properties. Residual stress and internal strain were characterized by an extended small-angle sin (2)psi method and the Williamson-Hall plot method, respectively. The results showed that the relationship of transition temperature Tc had the same variation trend as that of the strain. The existence of compressive stress was confirmed in YBa2Cu3O7-x/LaAlO3 samples while YBa2Cu3O7-x/LSAT and YBa2Cu3O7-x/SrTiO3 samples displayed tensile stress. Moreover, by controlling appropriate macroscopic residual stress and microscopic internal strain would be an indispensable method for tailoring the microstructures and superconducting properties.