Compositional segregation, structural transformation and property-temperature relationship of high-Curie temperature Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 single crystals

Abstract

Ternary ferroelectric single crystal Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 (PIN–PMN–PT) was grown by the modified Bridgman method. The compositional variation of different regions of the crystals was measured, and the segregation regularity of the crystals was proposed. Variations in the dielectric properties and domain structures of the PIN–PMN–PT single crystals were investigated as a function of temperature and composition, and the phase transformation behavior of the crystals was observed. The PIN–PMN–PT crystals showed high Curie temperatures (T C = 160–210 °C), ferroelectric phase transition temperatures (T R–T up to 132 °C) and coercive fields (E C = 6–8 kV/cm) as well as excellent piezoelectric properties (d 33 up to 2,800 pC/N) and electromechanical coefficients (k 33 > 0.90). As the temperature increased, k 33 values remained relatively constant and d 33 increased gradually prior to ferroelectric phase transformation, and these results reflect the wide temperature usage range of PIN–PMN–PT single crystals. The polarization (P r ) and E C of the crystals showed unique trends during the phase transformation process; high P r and E C values can be maintained prior to depolarization, which indicates that the PIN–PMN–PT single crystals are candidate materials for high-power applications. In summary, PIN–PMN–PT single crystals with ultrahigh electric properties, large coercive fields and excellent thermal stability may potentially be applied in harsh environments.