Eleventh International Conference on Internal Friction and Ultrasonic Attenuation in Solids
J. Phys. IV France 06 (1996) C8-687-C8-690
Mechanical Loss and Elastic Modulus Associated with Phase Transitions in PLZT CeramicsB.L. Cheng1, M. Gabbay2, M. Gimenez3 and G. Fantozzi2
1 Department of Physics, South China University of Technology, Guangzhou 510641, China
2 GEMPPM, UMR 5510 du CNRS, INSA Lyon, Bât. 502, 69621 Villeurbanne, France
3 Depto. Fisica de Los Materiales, UNED, Ciudad Universitaria, 28040 Madrid, Spain
The phase transition in lanthanum modified lead zirconate-titanate ceramic of 6/60/40 is studied by mechanical loss Q-1 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-1 curves at low frequencies show clearly a peak corresponding to such phase transition. This phase transition is confirmed by measurements of Young's modulus and Q-1 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 FE1 in the ferroelectric state. These phase transitions are also studied by DSC measurement.
© EDP Sciences 1996