Dielectric and field-induced strain behavior of modified lead zirconate titanate ceramics

Dielectric and field-induced strain behavior of the Pb0.97Y0.02[(Zr0.6Sn0.4)1-yTiy]O3 ceramics (PYZST) has been investigated as a function of Ti4+ content (0.07≤y≤0.20) and temperature. A structural change from the orthorhombic to rhombohedral phase was observed with increasing Ti4+ concentration, accompanied by the antiferroelectric to ferroelectric phase transition. As the temperature increases from the room temperature, the specimens of the composition with y≤0.12 undergo phase transitions from the ferroelectric rhombohedral to paraelectric cubic through antiferroelectric orthorhombic. The specimens with compositions near the antiferroelectric-ferroelectric phase boundary exhibited digital-type strain curve with the shape memory effect due to the antiferroelectric to ferroelectric phase transition. In the specimen of y=0.085, the electric field for the antiferroelectric to ferroelectric phase transition was 32kV/cm and the field-induced strain accompanied by the phase transition was 3x10-3. In addition, a temperature-composition phase diagram was determined from the study of crystal structure and the dielectric and field-induced strain properties.