Study of strain relaxation of YBa2Cu3O7-δ film grown on SrTiO3 and LaAlO3

Electron backscatter diffraction (EBSD) employed in scanning electron microscopy (SEM) is introduced to study the orientations of individual grains, sub-grains, and domains of YBa2Cu3O7-delta (YBCO) films grown on SrTiO3 (STO) and LaAlO3 (LAO), High resolution transmission electron microscopy (HR TEM) has been used to further study the epitaxial crystalline qualities. We have demonstrated that in addition to the ordinary strain-released phenomena, like dislocations in YBCO films on STO, there is another more effective way to release the epitaxial strain for YBCO films grown on LAO which comes from the 90 degrees domains.