Investigations on electrical and energy storage behaviour of PZN-PT, PMN-PT, PZN-PMN-PT piezoelectric solid solutions

Electrical response and energy storage behaviour of PZN-PT, PMN-PT, PZN-PMN-PT (PZN-PbZnl/3Nb2/3O3, PMN-PbMg1/3Nb2/3O3 and PT-PbTiO3) solid solutions were investigated. SEM micrographs of the sample showed grains of unequal sizes distributed throughout the sample. The average grain size observed was about 0.77m for PZN-PT, 0.93 for PMN-PT and 1.82 for PZN-PMN-PT solid solutions. All the solid solutions exhibited good dielectric relaxation behaviour up to 500 degrees C in the frequency range of 1-2MHz. The solid solutions showed improved ferroelectric properties (P-r similar to 17.4Ccm(-2), E-c similar to 3.65kVcm(-1), P-m similar to 20.1Ccm(-2) for PZN-PT) and crossover from nonergodic to ergodic relaxor phase with respect to temperature. The optimum piezoelectric coefficients, the piezoelectric voltage coefficients of the solid solutions were also studied. P-E loop analysis confirmed high energy storage density (W) of 0.25Jcm(-3) at 50kVcm(-1) for PZN-PMN-PT which substantiates its wide use in capacitor applications.