Magnetic properties of NiFe2O4 thin films grown on La0.7Sr0.3MnO3-buffered Si substrate

Nickel ferrite NiFe2O4 (NFO) thin films have been prepared on a Si substrate (NFO/Si) and La0.7Sr0.3MnO3 (LSMO)-coated Si (100) substrate (NFO/LSMO/Si) by RF magnetron sputtering. The microstructures and magnetic properties of the two films were systematically investigated. X-ray diffraction (XRD) and atomic force microscopy (AFM) revealed that highly (331)-oriented NFO films with a smooth surface were grown on the LSMO/Si substrate. The magnetization of the films was measured at room temperature. It showed a clear hysteresis loop in both samples, with the magnetic field applied in the plane. However, no hysteresis loop is seen with the magnetic field applied perpendicular to the film plane. This indicates the presence of an anisotropy favoring the orientation of the magnetization in the direction parallel to the film plane. A study of magnetization hysteresis loop measurements indicates that the LSMO buffer layer may improve the magnetic properties of NFO thin films, and that the saturation magnetization increases from 4.15 × 104 to 3.5 × 105 A/m.

► Nickel ferrite NiFe2O4 (NFO) thin films were prepared on Si substrate.
► The La0.7Sr0.3MnO3 buffer layer can improve the magnetic proerties of thin film.
► The enhanced magnetic moment may be attributed to the cationic inversion in NFO.