Dielectric and Piezoelectric Properties of 0.91Pb(Zn_1/3Nb_2/3)O₃-0.09PbTiO₃ Single Crystals

TLDR

The study investigates the dielectric, piezoelectric, and elastic properties of 0.91Pb(Zn1/3Nb2/3)O3–0.09PbTiO3 single crystals as functions of temperature and applied electric field. The properties were measured over a range of temperatures and electric fields to capture phase transitions and material responses. The crystals exhibit two first‑order phase transitions at 68 °C and 178 °C (rhombohedral→tetragonal→cubic) with slightly diffused transitions, accompanied by marked increases in dielectric, piezoelectric, and elastic constants at the lower transition and exceptionally high room‑temperature piezoelectric (d≈1500 pC/N) and coupling (k≈0.92) values when poled along the pseudo‑cubic [001] axis.

Abstract

The dielectric, piezoelectric and elastic properties of 0.91(PbZn 1/3 Nb 2/3 )O 3 –0.09PbTiO 3 single crystals have been investigated as functions of temperature and applied electric field. Two multiple phase transitions at 68°C and 178°C, the crystal changing from the rhombohedral ferroelectric phase to tetragonal ferroelectric and then to cubic paraelectric, have been observed. Both the transitions are of first-order, but both are slightly diffused. Significant increases in the dielectric, piezoelectric and elastic constants are observed at the lower transition point. In particular, the sample poled along the pseudo-cubic [001] axis reveals anomalously large piezoelectric and electro-mechanical coupling constants at room temperature in the rhombohedral phase ( d [001]// =1500×10 -12 C/N, k [001]// =0.92).