Effects of In3+ site occupancy on the magnetic properties of M-type strontium hexaferrites

Chul Sung Kim,Sunghyun Yoon,Bongjae Kim

doi:10.1063/1.5130073

Chul Sung Kim, Sunghyun Yoon + Show 1 more

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https://doi.org/10.1063/1.5130073

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Journal: AIP Advances	Publication Date: Jan 1, 2020
Citations: 9	License type: cc-by

Affiliation: Kookmin University, Kunsan National University

Abstract

Effects of nonmagnetic indium ion substitution on magnetic properties of M-type strontium hexaferrites SrFe12-xInxO19 (x=0, 0.25, 0.5, 0.75, and 1) have been studied by crystallographic and magnetic measurements. Samples were prepared by citric auto-combustion method. Rietveld analysis of X-ray diffraction profiles showed that the samples were single phase with the space group P63/mmc and lattice constants a and c increased linearly with In3+ content. Mössbauer spectra showed that In3+ mainly replaced Fe3+ ions in 4f2 sites and that 12k subspectra split into two distinct components 12k1 and 12k2. Analysis of hysteresis curves showed that while the coercive force and the magnetic anisotropy constant decreased thru the whole doping range x, the saturation magnetization first increased until x=0.5 and decreased thereafter. This behavior was explained by the existence of two competing interactions in terms of nonmagnetic indium substitution.

Highlights

Unlike the spinel and garnet ferrites, magnetoplumbite Mtype hexaferrites MFe12O19 (M=Ba, Sr, Pb etc.) are known to have as many as five kinds of interstitial sites that can accommodate transition metal ions
A series of studies on nonmagnetic substitution in Mtype hexaferrites have attracted considerable attention because Al3+ addition in Ba- or Sr-hexaferrites was found to extend the coercivity the saturation magnetization decreased with increasing Al3+ content
Magnetic anisotropy constant K are calculated from the hysteresis curves using the law of approach to saturation method10 and the results are listed in Table I, in which the magnetic anisotropy obviously decreases with In3+ substitution

Summary

Introduction

Unlike the spinel and garnet ferrites, magnetoplumbite Mtype hexaferrites MFe12O19 (M=Ba, Sr, Pb etc.) are known to have as many as five kinds of interstitial sites that can accommodate transition metal ions. A series of studies on nonmagnetic substitution in Mtype hexaferrites have attracted considerable attention because Al3+ addition in Ba- or Sr-hexaferrites was found to extend the coercivity the saturation magnetization decreased with increasing Al3+ content.1,2 Many experimental and theoretical researches have investigated the modifications in magnetic properties of M-type hexaferrites by replacing Fe3+ with diamagnetic Al3+, Ga3+, In3+, and Sc3+.

Results

Conclusion