Two high-temperature paraelectric phases in Sr0.85Bi2.1Ta2O9 - art. no. 100102

Authors
Hervoches, CH Irvine, JTS Lightfoot, P
Citation
Ch. Hervoches et al., Two high-temperature paraelectric phases in Sr0.85Bi2.1Ta2O9 - art. no. 100102, PHYS REV B, 6410(10), 2001, pp. 0102
Citations number
12
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
PHYSICAL REVIEW B
ISSN journal
01631829 → ACNP
Volume
6410
Issue
10
Year of publication
2001
Database
ISI
SICI code
0163-1829(20010901)6410:10<0102:THPPIS>2.0.ZU;2-6
Abstract
Sr0.85Bi2.1Ta2O9 is shown, by Rietveld refinement of powder neutron-diffrac tion data, to undergo two phase transitions at elevated temperature. The lo w-temperature ferroelectric phase (space group A2(1)am) transforms to a par aelectric phase (Amam) at T(c)similar to 375 degreesC. This phase does not transform to the expected tetragonal phase (I4/mmm) until T similar to 550 degreesC. The transition from A2(1)am to Amam involves not only loss of the displacive mode along the polar a axis, but also loss of a TaO6 octahedral tilt mode around the c axis.