Mechanical Loss and Elastic Modulus Associated with Phase Transitions in PLZT Ceramics

Abstract

The phase transition in lanthanum modified lead zirconate-titanate ceramic of 6/60/40 is studied by mechanical loss Q-I and elastic modulus measurements. The shear elastic modulus measured from 50°C to 250°C shows that the Curie temperature is located at 180°C for the transition from cubic to rhombohedral phase. The Q-' curves at low frequencies show clearly a peak corresponding to such phase transition. This phase transition is c o n f m e d by measurements of Young's modulus and Q-I using resonance curve technique from-100°C to 300°C at kilohertz. Moreover, between 50°C and 90°C, the resonance curve recorded at kHz frequency shows two resonance peaks. Such existence of double peaks means that a phase transition takes place between two rhombohedral phases FE2 and FEl in the fenpelectric state. These phase transitions are also studied by DSC measurement.

Internal friction in hard and soft PZT-based ceramics

“…Similarly to our case, Q À1 (T) curves on PLZT 6/60/40 show two peaks of phase transitions. 9 Previous results 16 on PLZT x/65/35 (x at.% La) have associated those P 2 and P 1 peaks to the rhombohedral1-rhombohedral2 and rhombohedral2 (ferroelectric)-cubic (paraelectric) phase transitions, respectively. The substitution of lead by lanthanum ions involves a decrease 17 of the Curie temperature in the PZT solid solution.…”

Phase transition study in PLZT ferroelectric ceramics by mechanical and dielectric spectroscopies

“…structural aspects of the local phase transformations and the phase transformation pathway between cubic and glassy states remain unclear. Concerning the elastic properties of PLZT, few experimental data [10][11][12][13][14][15] are available in the literature.…”

Study of the Anelastic Behavior of PZT and PLZT Ferroelectric Ceramics

“…The study of the internal friction (Q -1 ) and dynamic Young's modulus E can provide extensive information about the physics of the processes occurring within the materials. Internal friction measurements have been widely used in the field of metallurgy, but in the study of ferroelectric materials, specifically in PZT and PLZT ceramics, internal friction is seldom analyzed and few experimental data [9,10,11,12,13,14] are available in the literature.…”