Electric-field-induced phase transition of <001> oriented Pb(Mg1/3Nb2/3)O3-PbTiO3 single crystals

TL;DR

This study investigates how different electric field strengths induce phase transitions in <001> oriented Pb(Mg1/3Nb2/3)O3-PbTiO3 single crystals, revealing the dependence of phase change on poling intensity and its impact on piezoelectric properties.

Contribution

It demonstrates the electric-field-induced phase transition mechanisms in oriented PMN-PT single crystals and how poling strength influences phase states and piezoelectric performance.

Findings

Weaker poling field induces transition from microdomain to macrodomain rhombohedral phase.

Stronger poling field causes rhombohedral to tetragonal phase transition.

Higher piezoelectric constant observed at lower poling field (d33>1500 pC/N).

Abstract

<001> oriented 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 single crystals were poled under different electric fields, i.e. Epoling=4 kV/cm and Epoling=13 kV/cm. In addition to the temperature-dependent dielectric constant measurement, X-ray diffraction was also used to identify the poling-induced phase transitions. Results showed that the phase transition significantly depends on the poling intensity. A weaker field (Epoling=4 kV/cm) can overcome the effect of random internal field to perform the phase transition from rhombohedral ferroelectric state with short range ordering (microdomain) FESRO to rhombohedral ferroelectric state with long range ordering (macrodomain) FElRO. But the rhombohedral ferroelectric to tetragonal ferroelectric phase transition originating from <111> to <001> polarization rotation can only be induced by a stronger field (Epoling=13 kV/cm). The sample poled at Epoling=4 kV/cm showed higher piezoelectric constant, d33>1500 pC/N, than the sample poled at Epoling=13 kV/cm.