Study of magnetoelastic interaction in MnF2 by the acoustoelectric transformation method
I. V. Bilych1, K. R. Zhekov1, T. N. Haidamak1, G. A. Zvyagina1, D. V. Fil2,3, and V. D. Fil1
1B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine Kharkiv 61103, Ukraine
2Institute for Single Crystals of the National Academy of Sciences of Ukraine, Kharkiv 61072, Ukraine
3V. N. Karazin Kharkiv National University, Kharkiv 61022, Ukraine
Received February 22, 2022, published online May 20, 2022
The mechanisms of magnetoelastic interaction in MnF2 are studied using the method of acoustoelectric transformation. The temperature dependence of the piezomagnetic coupling coefficient and its anisotropy were 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.
Key words: MnF2, piezomagnetism, magnetoelastisity, magnetic susceptibility.