Soft modes in order-disorder ferroelectrics

Citation
Zr. Liu et al., Soft modes in order-disorder ferroelectrics, APPL PHYS L, 79(9), 2001, pp. 1333-1335
Citations number
12
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
APPLIED PHYSICS LETTERS
ISSN journal
0003-6951 → ACNP
Volume
79
Issue
9
Year of publication
2001
Pages
1333 - 1335
Database
ISI
SICI code
0003-6951(20010827)79:9<1333:SMIOF>2.0.ZU;2-2
Abstract
We find that the conventional method to calculate the soft-mode frequency o f the pseudospin model is incorrect, and present a valid modified method. I t is demonstrated that the conventional method does not show the soft-mode frequency going to zero at a critical temperature in the presence of random internal fields, while the frequency calculated by our modified method goe s to zero in random fields at a critical temperature. For the field-induced phase transition relaxor ferroelectrics, the soft-mode frequency decreases to zero at the first-order phase transition temperature though the symmetr y has been destroyed at high temperatures under an external field. (C) 2001 American Institute of Physics.