Brillouin scattering from transverse-acoustic modes of SrTiO3 is observed, while the frequencies of the soft polar modes are remeasured with hyper-Raman scattering. It is shown that an anomalous decrease of sound velocities at low temperatures results from the.coupling of the strain with the gradient of the electrical polarization fluctuations. The corresponding anomaly in the acoustic width indicates an inhomogeneous broadening of the soft polar mode.
Title
Brillouin-scattering observation of the TA-TO coupling in SrTiO3
Published in
Physical Review B
Volume
57
Issue
22
Pages
R13989-R13992
Date
1998
ISSN
0163-1829
Note
Hehlen, B Univ Montpellier 2, Lab Verres, CNRS, UMR 5587, F-34095 Montpellier 5, France Univ Montpellier 2, Lab Verres, CNRS, UMR 5587, F-34095 Montpellier 5, France Inst Max Von Laue Paul Langevin, F-38042 Grenoble, France Ecole Polytech Fed Lausanne, Lab Ceram, CH-1015 Lausanne, Switzerland Hokkaido Univ, Res Inst Elect Sci, Sapporo, Hokkaido 060, Japan
Zu948
Cited References Count:32
Record creation date
2006-08-21