Department of Physics and Astronomy: Publications and Other Research

John R. Hardy Papers
Document Type
Article
Date of this Version
9-15-1973
Citation
Physical Review (September 15, 1973) 8(6)
Abstract
90 °-scattered Raman spectra of single-domain gadolinium molybdate have been obtained at room temperature and above the 159 °C ferroelectric transition on several crystal orientations. Lines in the 0-200-cm-1 range can all be associated with Raman-active phonons and are identified by symmetry considerations, scattering-efficiency calculations, and comparison of spectra for different crystal orientations. Lines in the 200-1000-cm-1 range can be identified with coupled vibrations of tetrahedral molybdate ions. Spectra for frequencies above 1,000 cm-1 originate from impurity flourescence. The effect of the presence of multiple domains on the spectra was determined; the observed differences between single-domain and multiple-domain crystals result from B1-B2 symmetry mixing from the twinning of adjacent domains. No new soft modes, in addition to the known soft mode at about 43 cm-1, were observed. A few of the lines that are present in only the low-temperature phase cannot be identified from symmetry analysis and are probably derived from zone-boundary modes of the high-temperature phase.
Comments
Copyright 1973, American Physical Society. Used by permission