Splitting of libration mode frequencies in the vicinity of orientation phase transition in NH4Br

Authors
Glazkov, VP Somenkov, VA Syrykh, GF Savenko, BN
Citation
Vp. Glazkov et al., Splitting of libration mode frequencies in the vicinity of orientation phase transition in NH4Br, HIGH PR RES, 17(3-6), 2000, pp. 289-295
Citations number
13
Categorie Soggetti
Physics
Journal title
HIGH PRESSURE RESEARCH
ISSN journal
08957959 → ACNP
Volume
17
Issue
3-6
Year of publication
2000
Pages
289 - 295
Database
ISI
SICI code
0895-7959(2000)17:3-6<289:SOLMFI>2.0.ZU;2-O
Abstract
Vibrational spectra of NH4Br at high pressures up to 4.5 GPa have been stud ied by means of incoherent inelastic neutron scattering using sapphire anvi l high pressure cell technique. Libration mode splitting was investigated i n the vicinity of the orientation phase transition (P-tr=2.7 GPa) and this effect disappears if pressure is less or higher than P-tr. This effect is e xplained in terms of two-well asymmetric potential.