THE MAGNETOPHONON EFFECT

This article is a review of the magnetophonon effect, covering its origins, uses and the information which derives from it. The magnetophonon effect arises due to resonant phonon emission or absorption by free charge carriers in a solid in a high magnetic field. An example of this is when longitudinal optic (L. O. ) phonons are absorbed by electrons or holes in a semiconductor, causing resonant transitions between Landau levels. These transitions cause resonances in different transport parameters, such as resistivity, Hall and Seebeck coefficients. The article reviews the observation of normal magnetophonon resonances in semiconducting and semimetallic materials including alloys, p-type materials and semiconductor heterostructures. The hot-electron magnetophonon effect, which results from resonant electron cooling, and gives information on the electron energy loss mechanisms. This review was completed in December 1984.