Spin canting observation and cation distribution in CoFe2−xInxO4 (0.0 ⩽ x ⩽ 1.0) ferrites through low temperature–high field Mössbauer spectral study

Abstract

In the present work, In3+ substituted cobalt ferrites (CoFe2−xInxO4, x=0.0, 0.2, 0.4, 0.6, 0.8, 1.0) have been synthesized via solid-state reaction technique. The Rietveld fitted X-ray diffraction patterns confirm the formation of single phase cubic spinel structure with space group Fd3¯m for all the samples, with additional slight traces of secondary phase for x=0.6, 0.8 and 1.0 samples. The low temperature (5K)–high field Mössbauer (5T) spectra are analyzed in detail for probing the magnetic properties of Fe based In3+ substituted cobalt ferrites. The canted spin structures associated with Fe3+ ions both at A- and B-sites in the presence of external magnetic field of 5T have been noticed in all the samples. A fair agreement is obtained between the experimental integrated intensity ratios of 57Fe Mössbauer spectra at A- and B-sites and those calculated on the basis of cation distribution. The effect of In3+ substitution on various Mössbauer parameters viz hyperfine field distribution, isomer shift, quadrupole splitting and the line width has also been noticed. The magnetization measurements performed at low temperature also reveal the canted spin structures in all the samples. The variations in initial permeability over a wide range of frequency (125kHz–30MHz) at 300K have also been recorded. The initial permeability study reveals the occurrence of resonance phenomenon at very high frequencies which widens the area of utility of considered ferrites in the larger operational frequency range for various industrial applications.