Lattice dynamics of the layered compounds InI and InBr
Contributors: B.P. Clayman, Robert J. Nemanich, J.C. Mikkelsen Jr., G. Lucovsky
ABSTRACT
The lattice dynamics of the layered compounds InI and InBr are probed with the use of ir and Raman spectroscopy. These materials exhibit a puckered layer structure in which the halide ions are fivefold coordinated and the indium ions are sevenfold coordinated. While this material is anisotropic, the ir results were surprisingly independent of orientation and material. The Raman spectra are reported with the samples at both liquid-helium and room temperature. For InI six modes are observed, consistent with group-theory analysis, while for InBr five modes are observed. Simple valence-force models are discussed.