High-Pressure Effect on PbTiO3: An Investigation by Raman and X-Ray Scattering up to 63 GPa

We report a room-temperature high-pressure x-ray and Raman scattering investigation of lead titanate (PbTiO3) up to 63 GPa. Three continuous phase transitions at 13, 20, and 45 GPa between tetragonal-like phases occur. As a result, no evidence is found for a pressure-induced morphotropic phase boundary. Our study provides experimental evidence that PbTiO3 presents a complex sequence of phases accommodating pressure through mechanisms involving oxygen octahedra tilting and reentrance of ferroelectricity.