Bulk and Thin Film Properties of (Pb, La)TiO3 Ferroelectrics

Dielectric, electrooptic, mechanical properties of ferroelectric ceramics including (Pb, La)TiO3 are described. PbTiO3 is a ferroelectric material with a higher Curie point (about 500°C) and a larger tetragonality (c/a = 1.06) compared to BaTiO3 (Curie point of 120°C and tetragonality of c/a = 1.01). PbTiO3 ceramics are very difficult to sinter because of this large tetragonality. When PbTiO3 is doped with La, the tetragonality, Curie point, and internal stress incurred during the cubic-to-tetragonal transition all decrease.