First-principles calculation of magnetoelastic coefficients and magnetostriction in the spinel ferrites CoFe2O4 and NiFe2O4

TL;DR

This study uses density functional theory to calculate magnetostriction constants in CoFe2O4 and NiFe2O4, examining how cation arrangements influence their magnetoelastic properties and aligning well with experimental data.

Contribution

It provides the first-principles calculation of magnetoelastic coefficients in spinel ferrites, highlighting the effects of cation distribution on their magnetic and elastic properties.

Findings

Magnetostriction constants agree with experimental data.

Cation distribution affects CoFe2O4 more than NiFe2O4.

Elastic constants are largely unaffected by cation arrangements.

Abstract

We present calculations of magnetostriction constants for the spinel ferrites CoFe2O4 and NiFe2O4 using density functional theory within the GGA+U approach. Special emphasis is devoted to the influence of different possible cation distributions on the B site sublattice of the inverse spinel structure on the calculated elastic and magnetoelastic constants. We show that the resulting symmetry-lowering has only a negligible effect on the elastic constants of both systems as well as on the magnetoelastic response of NiFe2O4, whereas the magnetoelastic response of CoFe2O4 depends more strongly on the specific cation arrangement. In all cases our calculated magnetostriction constants are in good agreement with available experimental data. Our work thus paves the way for more detailed first-principles studies regarding the effect of stoichiometry and cation inversion on the magnetostrictive properties of spinel ferrites.