RT info:eu-repo/semantics/article
T1 Effect of pressure on the Raman anomaly of zinc-blende CuBr and Raman spectra of high-pressure phases
A1 Manjón, F. J.
A1 Loa, I.
A1 Syassen, K.
A1 Lin, C. T.
A1 Cardona, M.
A1 Serrano Gutiérrez, Jorge
AB Raman spectra of isotopically pure CuBr (63Cu81Br) were measured under hydrostatic pressures up to 10 GPa at 10 K. The anomalous line shape of the longitudinal-optic (LO) scattering in the zinc-blende phase (CuBr-III, 0–4 GPa), consisting of a broad structure between 155 and 177cm−1, exhibits a continuous change with pressure and develops into a narrow LO phonon peak near 4 GPa. The disappearance of the LO Raman anomaly as well as the pronounced broadening of the TO mode with pressure are explained in terms of pressure-dependent third-order anharmonic interactions with two-phonon states. A Fermi resonance model, which is based on a shell model fit of available phonon dispersion data, fully accounts for the changes in Raman line shapes under pressure. Low-temperature Raman spectra of the tetragonal CuBr-IV and cubic CuBr-V high-pressure phases are also reported. An assignment of the observed Raman modes of these phases is proposed.
PB American Physical Society
SN 0163-1829
YR 2001
FD 2001
LK https://uvadoc.uva.es/handle/10324/65356
UL https://uvadoc.uva.es/handle/10324/65356
LA eng
NO Phys. Rev. B 64, 064301 (2001)
DS UVaDOC
RD 06-ago-2024