Magnetic Hyperfine Structure of Epitaxial Films of Nickel Ferrite

Abstract

Comparative NGR study of the parameters of the magnetic hyperfine structure of epitaxial NiFe2O4 films grown on MgO single-crystal substrates of orientations of (100) and (111) by liquid phase epitaxy (LPE) and chemical transport reactions (CTR) is conducted. It is established that in the films obtained by the method of CTR, there is a significant number of ions of bivalent iron, which is in phase magnetite Fe2+Fe23+O4 . After heat treatment of these films in air at T = 1273 K, the magnetite becomes the Fe2O3 oxide. In the films of NiFe2O4, grown by the LPE method the divalent iron was not detected. As shown by calculations, the vector direction of the magnetization of films obtained by the method of LPE, lies in the film plane regardless of the orientation (100) or (111) MgO substrates. In films obtained by the CTR method, it forms with the substrate 41 - 450. Keywords: liquid phase epitaxy, chemical transport reactions, ferrite films, magnetic anisotropy, nuclear gamma resonance.