Phase Transitions, Piezo- and Ferroelectric Properties of BiScO₃-PbTiO₃ Solid Solutions

Abstract

Ceramic solid solutions (1-x)(Bi_0.9Nd_0.1)(Sc_0.9B_0.1)O₃ - xPbTiO₃ (x = 0.60–0.66; B - Lu, Yb, Er, Y) based on the compositions close to the morphotropic boundary, have been prepared. To improve the phase content and the resistance of ceramics, Bi₂O₃ and MnO₂ additives were used. Phase composition, structure, microstructure, phase transitions, ferroelectric and piezoelectric properties have been studied. The 1^st order ferroelectric phase transitions are marked by peaks near 700–750 K in dielectric permittivity and dielectric loss temperature dependences. Effect of dielectric relaxation was observed, its relation to composition of ceramics determined. The Curie temperature T_C increase was observed with increasing the PbTiO₃ constituent, while the T_C decrease is typical of the A- or B-cations doped compositions. Introduction of MnO₂ and/or Bi₂O₃ additives lead to the decrease of total conductivity and dielectric losses to more than one order at elevated temperatures. Enhanced d₃₃ and k_t values were measured in modified ceramics.

Keywords:

• BiScO₃ - PbTiO₃ ceramics
• ferroelectrics, piezoelectrics properties

Acknowlegment

The work is supported by the Russian Fund for Basic Research (Grant 10-03-91161).