Surface acoustic wave propagation in MnF2

Abstract

The temperature and magnetic field dependence of surface acoustic wave velocities in MnF2 single crystals has been investigated. Wave propagation was on a free (001)-plane in [100] and [110]-direction. The temperature dependence can be explained quantitatively by an elastic continuum approach. Experiments reveal the bulk spin flop at Bc∼9.3 T at 4.2 K. No evidence is found for a surface spin flop at lower field, B sc∼6.6 T.