Internal friction and dielectric permittivity studies: barium lead titanate ferroelectric ceramics

Barium titanate (BT) has become one of the most important electroceramics since the discovery of its varied applications. Because of these important applications, there has been a great deal of interest in both the fabrication and the electrical properties of modified BT-based ceramics. Ba_0.8Pb_0.2TiO₃ (BPT) ferroelectric ceramic was prepared by the conventional ceramic method. X-ray diffraction and SEM confirmed single-phase BPT. Temperature variations of dielectric constant, dielectric loss, longitudinal modulus and internal friction were measured. The electrical properties of BT-based ceramics depend strongly on both microstructure and composition. Dielectric properties and mechanical properties have been discussed in relation to phase transitions.