Growth and characterization of BLZT–CFO composite thin films

Composite Ba0.90La0.067Zr0.09Ti0.91O3–CoFe2O4 (BLZT–CFO) thin films were prepared by rf-magnetron sputtering from a 0.68 BLZT–0.32 CFO mixed target at a substrate temperature of 1033 K in a high oxygen pressure atmosphere. Single-crystal conducting Nb-doped (1%) SrTiO3 and Pt-coated Si substrates were used. X-ray diffraction (XRD) patterns revealed that the films had both BLZT and CFO phases. Scanning electron microscopy (SEM) showed that the CFO phase was intermixed into a BLZT matrix. X-ray photoelectron spectroscopy (XPS) data in depth profile mode showed that all constituent elements were present and confirmed the favourable TiO6-octahedron distortion in the BLZT-perovskite structure. The Au/BLZT–CFO/substrate capacitors were ferroelectric and magnetic at room temperature. The magnetoelectric nature of the composite thin films was demonstrated through the reduction of measured ferroelectric polarization with the application of an external magnetic field.