Compensation effect and magnetostriction in CoCr2-xFexO4

TL;DR

This study investigates how Fe doping affects the magnetic compensation, magnetostriction, and magnetic interactions in CoCr2O4, revealing site occupation changes, compensation phenomena, and the first observation of magnetostriction in this system.

Contribution

It provides new insights into Fe doping effects on magnetic site occupation, compensation behavior, and reports the first magnetostriction measurement in CoCr2-xFexO4.

Findings

Magnetic compensation occurs at x=0.1 with temperature dependence.

Fe ions switch from B1(Cr) to A(Co) sites as doping increases.

Magnetostriction reaches about 280ppm at x=0.4.

Abstract

The magnetic compensation and magnetostriction properties in Fe doped CoCr2O4 samples have been investigated. Structural and magnetic measurements imply that the doped Fe3+ ions initially occupy the B1(Cr) sites when x<0.1, and then mainly take the A(Co) sites. This behaviour results in a role conversion of magnetic contributors and a composition compensation between two competitively magnetic sublattices at x=0.1. Temperature dependence compensation has also been found in the samples with x=0.1~0.22, with the compensation temperature in the range of 40~104 K. The Fe3+ doping also modulates the exchange interaction of the system and prevents the formation of long range conical order of spins. The magnetoelectric transition temperature at 23K in CoCr2O4 is shifted to lower temperature by increasing the dopants. The magnetostriction effect in this system has been observed for the first time. The strain has a maximum value of about 280ppm at x=0.4. The magnetostriction is in consistent with the behaviour of the two magnetic compensations.