Title:Raman scattering from solid helium at high pressure
Journal:Physical Review B: Condensed Matter
Coden:PRBMD
Issue:Vol. 31, No. 7
Issue Date:01 April 1985
Pages:4705-4707
Author:George H. Watson , Jr., William B. Daniels
Address:Department of Physics, University of Delaware, Newark, Delaware 19716

Abstract: Precise Raman measurements of high-density [sup 4]He have been made possible by improvements in high-pressure light scattering techniques. Raman spectra from hcp crystals with molar volumes of 7.74 and 9.06 cm[sup 3], representing compressions of = (approximately-equal-to) 60% from crystals at the lowest possible density, help to determine the applicability of conventional lattice dynamics to solid helium at high pressure. Temperature-dependent anharmonic effects were quantitatively observed for the first time and are interpreted in terms of specific phonon interactions.

Rct Date:(Received 26 December 1984)
PACS:Type: E-Experimental. Format L-Letter. Year: 85. Class nos. 67.80.Cx; 78.30.Gt
Country:US-United States
CPM no.: Microfilm no(s): 8504C2415 Abstract no(s): 2.05718
Keywords:Number: 07. ANHARMONICITY; TEMPERATURE DEPENDENCE; LATTICE DYNAMICS :Q1; PHONONS; SOLID HELIUM 4 :T1; RAMAN SPECTRA :Q1; VERY HIGH PRESSURE