Thermal Expansion Properties of Lanthanum‐Substituted Lead Titanate Ceramics

The Pb 1− x La x TiO 3 powders were prepared by a sol–gel route in the composition range from x =0.0 to 0.3 in 0.05 increments. The lattice parameters of Pb 1− x La x TiO 3 ( x =0.0, 0.05, 0.10, 0.15, 0.20, 0.30) were determined by a high temperature X‐ray diffraction, and the intrinsic thermal expansion coefficients were obtained in the temperature range from room temperature to 900°C. The Pb 1− x La x TiO 3 compounds ( x =0.10, 0.15, 0.20) in the tetragonal system exhibit low thermal expansion behaviors. As the La content is increased, the phase transition in the Pb 1− x La x TiO 3 changes continuously from conventional to diffuse phase transition.