Bound Magnon-Phonon Pairs in Metamagnetic Systems

Abstract
We calculate the magnon-phonon coupling for metamagnetic systems of the type FeCl ·2H2O. The coupling, which is derived from a microscopic point of view, is strong enough to bind a magnon to a phonon in some metamagnetic materials. An analysis of the coupling is presented for different systems, and the results are related to recent experimental data of Torrance and Hay.