OPTIC SOFT MODE IN FERROELASTIC BETAINE SQUARATE

Authors
ZIMMER HJ THEDENS H UNRUH HG
Citation
Hj. Zimmer et al., OPTIC SOFT MODE IN FERROELASTIC BETAINE SQUARATE, Ferroelectrics, 208(1-4), 1998, pp. 83-91
Citations number
11
Categorie Soggetti
Physics, Condensed Matter","Material Science
Journal title
Ferroelectrics → ACNP
ISSN journal
00150193
Volume
208
Issue
1-4
Year of publication
1998
Pages
83 - 91
Database
ISI
SICI code
0015-0193(1998)208:1-4<83:OSMIFB>2.0.ZU;2-K
Abstract
The ferroelastic transition of betaine squarate at T-c approximate to 52.7 K is shown to be driven by an optic mode. Raman spectroscopic inv estigations reveal a soft mode or A(2) symmetry, the eigenvector of wh ich couples bilinearly with the shear strain e(5), which represents th e order parameter. This coupling renormalizes the elastic stiffness c( 55) and eventually leads to the transition when c(55)(T) becomes zero at T-c.