Comparative study of magnetic-field-assisted liquid–vapour interfacial growth of CoFe2O4 and NiFe2O4 thin films
摘要
Controlling magnetic anisotropy during film growth is crucial for the development of next-generation spintronic and magnetic sensing devices. Transferrable, magnetically anisotropic CoFe2O4 and NiFe2O4 films were grown under out-of-plane and in-plane magnetic fields to investigate the effect of field orientation on their structural, morphological and magnetic properties. The films grown without an applied magnetic field were polycrystalline, whereas the application of magnetic field induced anisotropic growth with a preferred (220) orientation in both films. The out-of-plane and in-plane magnetic field resulted in vertical and lateral grain alignment, respectively. The applied magnetic field significantly enhanced texture in the films, increasing the lotgering factor from 0.40 (CoFe2O4) and 0.42 (NiFe2O4) to nearly unity under both in-plane and out-of-plane magnetic fields. Compared to in-plane field grown films, those grown under out-of-plane magnetic field showed smoother and more uniform surfaces. CoFe2O4 films showed stronger field-induced responses than NiFe2O4, evidenced by significantly increase in saturation magnetization (29.38 to 133.75 emu/cm3), coercivity (79.92 to 2301.12 Oe), and magnetocrystalline anisotropy (2.44 × 103 to 318.61 × 103 erg/cm3). Magnetic hysteresis loops were recorded at angular orientations of 0°, 90°, 180°, and 270° relative to the direction of the magnetic field applied during film growth. The angular-dependent magnetic measurements showed significant improvement in magnetic properties, particularly for films grown under in-plane magnetic fields. The findings demonstrate that the magnetic field assisted growth can provide a way for tuneable crystallographic orientation with magnetic anisotropy in magnetic films for suitable magnetic device applications.