Internal friction study of Pb(Zr,Ti)O3 ceramics with various Zr/Ti ratios and dopants

The Pb(Zr,Ti)O3 (PZT) ceramics with Zr/Ti ratios of 30/70, 52/48 and 70/30 and the PZT(52/48) ceramics doped with La, Ta and Co at various percent were prepared by a standard solid-state reaction method, respectively. Internal friction and modulus were measured as a function of temperature at low frequencies by using a inverted torsion pendulum. Two internal friction peaks (P1 and P2), related to oxygen vacancies and domain walls, respectively, were observed in all the undoped PZT ceramics with different Zr/Ti ratios. In addition, a minimum in modulus associated with a phase transition internal friction peak appearing at Curie temperature was observed in all samples. The effects of the Zr/Ti ratios and some dopants (such as La, Ta and Co) on the internal frictions were investigated. The internal friction results indicate the changes of the concentration of oxygen vacancies and the domain structure with the variations of Zr/Ti ratios and dopants, which will be helpful in the utilities of the PZT ceramics. (author)