FIR STUDIES OF ALPHA-POLYMORPHS AND BETA-POLYMORPHS OF LINH4SO4 SINGLE-CRYSTALS

Authors
POLOMSKA M HILCZER B BARAN J
Citation
M. Polomska et al., FIR STUDIES OF ALPHA-POLYMORPHS AND BETA-POLYMORPHS OF LINH4SO4 SINGLE-CRYSTALS, Journal of molecular structure, 325, 1994, pp. 105-110
Citations number
18
Categorie Soggetti
Chemistry Physical
Journal title
Journal of molecular structure → ACNP
ISSN journal
00222860
Volume
325
Year of publication
1994
Pages
105 - 110
Database
ISI
SICI code
0022-2860(1994)325:<105:FSOAAB>2.0.ZU;2-5
Abstract
LiNH4SO4 crystals occur in two polymorphous modifications. The alpha p olymorph (space group Pca2(1)) undergoes an irreversible transformatio n to the beta modification (space group Pc2(1)n) exhibiting a ferroela stic-paraelastic phase transition at about 284 K and a ferroelectric-p araelectric transition at T(c) almost-equal-to 460 K. Using FIR spectr oscopy we studied the differences in the external vibrations of the tw o polymorphs, and the alpha --> beta polymorphous transformation.