Study of magnetoelastic interaction in MnF$_2$ by the acoustoelectric transformation method

TL;DR

This study investigates the magnetoelastic interactions in MnF$_2$ using acoustoelectric transformation, revealing temperature-dependent coupling, anisotropy, and a new susceptibility tensor component linked to shear waves.

Contribution

It introduces a novel observation of a non-diagonal magnetic susceptibility component induced by shear waves in MnF$_2$, with a phenomenological interpretation.

Findings

Temperature dependence of piezomagnetic coupling coefficient determined.

Observation of a non-diagonal susceptibility component proportional to the square of the order parameter.

Reduction of acoustic deformation effects in the paramagnetic state.

Abstract

The mechanisms of magnetoelastic interaction in MnF$_2$ are studied using the method of acoustoelectric transformation. The temperature dependence of the piezomagnetic coupling coefficient and its anisotropy are determined in the antiferromagnetic phase. We observe a new effect consisting in the appearance of a non-diagonal component of the magnetic susceptibility tensor, which is proportional to the square of the order parameter, under the action of the shear wave. A phenomenological interpretation of the effect, which takes into account a small-angle rotation of the crystal lattice, is presented. In the paramagnetic state, the effect of acoustic deformation is reduced to the modulation of the diagonal component of the susceptibility tensor.