Study of the lattice dynamics of hexagonal close-packed3He and4He using inelastic x-ray scattering

Autor: R. O. Simmons, Eberhard Burkel, D. A. Arms, C. Seyfert, H. Sinn
Rok vydání: 1999
Předmět:
Zdroj: Journal of Physics: Condensed Matter. 11:3501-3511
ISSN: 1361-648X
0953-8984
DOI: 10.1088/0953-8984/11/17/308
Popis: We present the first measurement of the coherent dynamic structure factor S(Q,) of solid 3He. At a density of 13.25(10) cm3 mol-1, we observed longitudinal phonons, using high-resolution inelastic x-ray scattering at momentum transfers 6 nm-1 < |Q| < 23 nm-1. Their dispersion relation was determined along the c-axis in single crystals of hcp 3He, and the spectra were described with a single-phonon model. For comparison, hcp 4He at the same density was studied with the same technique. The comparison, including all available 4He data from neutron scattering experiments, results in a phonon frequency ratio 3/4 of 1.11(5). Special attention is given to the scattering contribution due to multi-phonon excitations.
Databáze: OpenAIRE