Observation of the coupling between TA and TO modes in SrTiO3 by Brillouin scattering
Brillouin scattering showing an unusual low temperature softening of some transverse modes in SrTiO3 had been reported previously. The earlier data, complemented by newer Brillouin results, and supplemented by high quality hyper Raman data on the soft mode, demonstrate that this anomalous softening is to a large extent caused by a bilinear coupling of the strain with the gradient of the electrical polarization fluctuations. This coupling had been identified long ago in KTaO3, but at the large momentum exchanges that are achieved in neutron spectroscopy. To our knowledge, it is the first time that the signature of this coupling is observed in any material at the small wave vectors of optical Brillouin scattering. (C) 1999 Elsevier Science B.V, All rights reserved.
- View record in Web of Science
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
Cited References Count:16
Record created on 2006-08-21, modified on 2016-08-08