Fermi resonance involving non-linear dynamical couplings in Pb(Zr,Ti)O.sub.3./sub. solid solutions

0368179 - FZÚ 2012 RIV US eng J - Journal Article
Wang, D. - Buixaderas, Elena - Iniguez, J. - Weerasinghe, J. - Wang, H. - Bellaiche, L.
Fermi resonance involving non-linear dynamical couplings in Pb(Zr,Ti)O₃ solid solutions.
Physical Review Letters. Roč. 107, č. 17 (2011), 175502/1-175502/5. ISSN 0031-9007. E-ISSN 1079-7114
R&D Projects: GA MŠMT ME08109
Institutional research plan: CEZ:AV0Z10100520
Keywords : phonons * lattice dynamics * PZT
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 7.370, year: 2011

We have used first-principles-based simulations and Raman scattering techniques to reveal a novel dynamical phenomenon in Pb(Zr,Ti)O3 solid solutions: a Fermi resonance (FR) emerging from the non-linear coupling between ferroelectric (FE) motions and tiltings of oxygen octahedra. This FR manifests itself as the doubling of a nominally-single FE mode in a purely FE phase, when the resonant frequency of the FE mode is close to the first overtone of the tiltings. We show that the FR is the result of a non-linear coupling that is proportional to the spontaneous polarization of the material, and derive an analytical model that captures the essence of the effect.
Permanent Link: http://hdl.handle.net/11104/0202593