Effect of Mn and Zn binary Co-substitution on structure and magnetic properties of cobalt ferrites

Abstract

Mn-Zn binary co-substituted cobalt ferrite (Co1-x(MnZn)xFe2O4 (0 ≤ x ≤ 0.4)) was synthesized by conventionally compacting and magnetic field assisted injection molding. XRD and SEM analysis characterized the single-phase spinel structure, preferred 〈001〉 orientation, and uniform grain size. XPS analysis reveals the cation redistribution in the mixed spinel structure of co-substituted samples, which has a direct consequence on magnetic properties. The addition of Mn-Zn increases the saturation magnetization (Ms), while decreases magnetocrystalline anisotropy constant (K1), leading to a decrease of magnetostrictive saturation field (HS). For pressure samples, the maximum (dλ/dH)max is −0.15 ppm/Oe under 300 Oe applied field at x = 0.2. The samples with 〈001〉 fiber texture were prepared by magnetic field alignment of the semi-solid slurry to achieve higher magnetostrictive properties. The highest magnetostriction λS reaches −432 ppm, which is 200 % higher than pressed samples, and the corresponding maximum strain derivative (dλ/dH)max reaches −0.88 ppm/Oe at a lower magnetic field.