The physical properties and microstructure of BiFeO3/YBCO heterostructures

Abstract The BiFeO 3 /YBCO heterostructures were fabricated on (001)-oriented SrTiO 3 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 BiFeO 3 /YBCO heterostructure were detected by transmission electron microscopy (TEM) proving the epitaxial growth of BiFeO 3 /YBCO heterostructures on SrTiO 3 . The edge dislocation with a Burgers vector [100] was observed in BiFeO 3 , which contributed to the relaxation of BiFeO 3 . The results of magnetization hysteresis cycles indicated that the saturation magnetization increased from 14 emu/cm 3 of BiFeO 3 /SrTiO 3 to 42 emu/cm 3 of BiFeO 3 /YBCO/SrTiO 3 . The second phase Fe 2 O 3 on the surface of BiFeO 3 was found to be α-Fe 2 O 3 with weak magnetization at room temperature. Therefore, the increased magnetization could be accounted for by the induced ferromagnetism at the interface of BiFeO 3 /YBCO.