Internal friction in hard and soft PZT-based ceramics

This study concerns the two following commercial ceramics: PZT TRS100 (US Navy I standard: hard material) and PZT TRS600 (US Navy VI standard: soft material). These materials are PZT ceramics with various dopants. Internal friction and elastic modulus measurements have been performed versus temperature at different frequencies. Considering the hard ceramic, two relaxation peaks (R1, R2) related to oxygen vacancies–domain walls interaction were observed similarly to undoped PZT ceramics. In addition, a phase transition peak (P1) occurs at the Curie temperature. Considering the soft ceramic, only two phase transition peaks were observed. The increase of modulus associated with the phase transition internal friction peak occurs at the Curie temperature in both samples. The effects of some dopants are investigated. Some of them influence either the concentration of oxygen vacancies or the domains structure.