LAUSR

Abstract The BiFeO3/YBCO heterostructures were fabricated on (001)-oriented SrTiO3 substrates by pulsed laser deposition. The superconducting transition temperature of YBCO was found to decline with increasing the c-axis parameter. The microstructure and dislocations in BiFeO3/YBCO heterostructure were detected by transmission electron microscopy (TEM) proving the epitaxial growth of BiFeO3/YBCO heterostructures on SrTiO3. The edge dislocation with a Burgers vector [100] was observed in BiFeO3, which contributed to the relaxation of BiFeO3. The results of magnetization hysteresis cycles indicated that the saturation magnetization increased from 14 emu/cm3 of BiFeO3/SrTiO3 to 42 emu/cm3 of BiFeO3/YBCO/SrTiO3. The second phase Fe2O3 on the surface of BiFeO3 was found to be α-Fe2O3 with weak magnetization at room temperature. Therefore, the increased magnetization could be accounted for by the induced ferromagnetism at the interface of BiFeO3/YBCO.