Neutron scattering studies of magnetic thin films and multilayers

Abstract

The basic principles of the elastic scattering of polarized neutrons from magnetic films and thin film superlattices, both kinematically as well as dynamically in the continuum limit, are summarized first. The quantitative accuracy presently attainable in practice is discussed along with other relevant issues regarding experimental technique and data analysis. Investigations of interlayer coupling and the effects of strain and finite thickness in single crystalline, epitaxially grown superlattices are reviewed, focussing on specular neutron diffraction and reflectivity measurements. These superlattices include rare earth and semiconductor systems in addition to those that exhibit “giant” magnetoresistive effects and which are of particular current technological interest. A survey of some of the more recent studies of the enhancement/reduction of ferromagnetic moments at an interface with a nonmagnetic material is then presented. Finally, several future research directions, for example, magnetic nonspecular scattering and studies of the magnetic state of the materials which form the intervening layers between coherently coupled ferromagnetic layers in superlattices, are discussed.