Raman study of phase transition and hydrogen bond symmetrization in solid DCl at high pressure

Citation
E. Katoh et al., Raman study of phase transition and hydrogen bond symmetrization in solid DCl at high pressure, PHYS REV B, 61(1), 2000, pp. 119-124
Citations number
23
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
PHYSICAL REVIEW B
ISSN journal
1098-0121 → ACNP
Volume
61
Issue
1
Year of publication
2000
Pages
119 - 124
Database
ISI
SICI code
1098-0121(20000101)61:1<119:RSOPTA>2.0.ZU;2-9
Abstract
Phase transitions in solid DCl have been investigated by Raman spectral mea surement up to 70 GPa at 298 K. The I-III phase transition accompanied by o rientational ordering of the molecules took place at 19.0 +/-0.5 GPa, exact ly the same pressure as observed for solid HCl. A further transition with h ydrogen bond symmetrization (III-IV transition) was observed at about 56+/- 2 GPa higher by 5 GPa than the symmetrization pressure of HCl previously de termined. The bond symmetrization is realized when the midpoint barrier sep arating two potential minima along the hydrogen-bonding axis is depressed a nd smeared out quantum mechanically. The observed isotope effects on the sy mmetrization pressure are hence interpreted in terms of proton (deuteron) t unneling transfer in the hydrogen bonding potential, which gradually is def ormed toward a single minimum shape with increasing pressures.