Optical Properties of the Europium Chalcogenide Magnetic Semiconductors

Abstract

The magnetic semiconductors of the europium chalcogenide family, EuO, EuS, EuSe and EuTe, form a system of NaCl structures with closely related lattice, electronic and magnetic properties. These materials all show a strong coupling between the electronic and the magnetic properties so that the electrical properties are greatly modified by a change of magnetic state. The chemical unit cells are all identical whereas the magnetic unit cells can vary greatly from one compound to another, depending on the magnetic state, even though the magnetic ion is the same (Eu²⁺) for each compound. These compounds have been studied by many investigators using a variety of techniques over a number of years. These lectures will cover the optical properties of these materials, including both the linear (absorption constants) and the non-linear (Raman scattering) response. A correlation between the electronic and lattice mode structure will be made based on these optical experiments.

Supported by the NSF.