TY - JOUR
T1 - Two high-temperature paraelectric phases in Sr0.85Bi2.1Ta2O9
AU - Hervoches, CH
AU - Irvine, John Thomas Sirr
AU - Lightfoot, Philip
PY - 2001/9
Y1 - 2001/9
N2 - Sr0.85Bi2.1Ta2O9 is shown, by Rietveld refinement of powder neutron-diffraction data, to undergo two phase transitions at elevated temperature. The low-temperature ferroelectric phase (space group A2(1)am) transforms to a paraelectric 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.
AB - Sr0.85Bi2.1Ta2O9 is shown, by Rietveld refinement of powder neutron-diffraction data, to undergo two phase transitions at elevated temperature. The low-temperature ferroelectric phase (space group A2(1)am) transforms to a paraelectric 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.
KW - FERROELECTRIC PROPERTIES
KW - SRBI2TA2O9
KW - TANTALATE
UR - http://www.scopus.com/inward/record.url?scp=0035444201&partnerID=8YFLogxK
UR - http://link.aps.org/abstract/PRB/v64/e100102
U2 - 10.1103/PhysRevB.64.100102
DO - 10.1103/PhysRevB.64.100102
M3 - Article
SN - 1098-0121
VL - 64
SP - 1001021
EP - 1001024
JO - Physical Review. B, Condensed matter and materials physics
JF - Physical Review. B, Condensed matter and materials physics
IS - 10
M1 - 100102
ER -