Structural studies of relaxor/ferroelectric Pb(Mg1/3Nb2/3)O-3/PbTiO3 superlattices
Résumé
We have synthesized [Pb(Mg1/3Nb2/3)O-3]((1-x)Lambda)/[PbTiO3](x Lambda) (PMN(1-x)LambdaPT(x)Lambda) super-lattices by pulsed laser ablation onto MgO substrates buffered with La1/2Sr1/2CoO3 (LSCO). We varied the composition (0.1 <= x <= 0.8), and kept the modulation period A constant at about 140 angstrom. X-ray diffraction indicates that the polar c-axis of the PT layers lies in the plane of the films. This is confirmed by the Raman spectra. There is a shift to lower frequencies of the PT soft mode due to stress but we observe no indications of stress dependence in the Raman spectra of the PMN layers.