Abstract

Samarium monosulfide is a phase transition material which, in bulk, is a semiconductor at ambient temperature and pressure. An increase of pressure or stress leads to a lattice collapse and first-order transition to a metallic state. Reactively evaporated thin films of SmS have a granular structure, and their optical response differs from that of the bulk. The response is modeled using data on the bulk material and a Bruggemen effective medium theory. When the phase transition is induced by mechanical abrasion of the films, only a portion of the material undergoes the lattice collapse. We model these switched films as a mixture of semiconducting and metallic grains in a dielectric matrix.

© 1985 Optical Society of America