Effect of high pressure on the Pb(Mg1/3Nb2/3)O3-PbTiO3 solid solution:: A Raman scattering investigation -: art. no. 134114

We report a high-pressure Raman scattering investigation of (1-x)Pb(Mg1/3Nb2/3)O-3-xPbTiO(3) (PMN-PTx), which is considered as a prototype relaxor-based piezoelectric. The observed spectral changes are important and it is the pressure-induced appearance of a sharp band at roughly 370 cm(-1) for all investigated PMN-PTx, that allows the construction of a partial x-p phase diagram which is characterized by a high-pressure non-cubic structure. This high-pressure structure is very similar if not identical to the high-pressure structure of PMN. Finally, we present a discussion of the high-wavenumber part of the Raman spectrum in terms of a two-mode behavior, which suggests a very local order around Ti atoms.