Sound propagation and its magnetic field dependence in an itinerant electron ferromagnet

Abstract

In this paper first we derive general expressions for the velocity and attenuation constant of longitudinal acoustic sound and their magnetic field dependence in an itenerant electron ferromagnet both for T<T c and T>T c. Then by carrying out numerical calculation on these quantities with a simple model electronic density of states we find them to reflect very sensitively the electronic structure and the exchange interaction between electrons of a metal. We emphasize the possibility of using such ultrasonic observation as a useful probe of electronic structure and electron interaction in a metal. Finally we point out that from these magnetic field effects on sound velocity we can infer the effect of the electron-phonon interaction on the magnetic properties of a metal.