Temperature and DC bias dependence of the phase transition behavior of [011]- and [001]-oriented PIN–PMN–PT single crystals with MPB composition

The phase transition behavior of [011]- and [001]-oriented 0.24PIN–0.43PMN–0.33PT single crystals was investigated through dielectric measurement in the process of heating and direct current (DC) bias. The phase transformation sequence in the [011]-oriented crystals is rhombohedral (R) → monoclinic (MB) → orthorhombic (O) → monoclinic (MC) → tetragonal (T) → cubic (C). The phase transition temperatures of R to MB(({{ m{T}}_{{ m{R}} - {{ m{M}}_{ m{B}}}}}))and MBto O(({{ m{T}}_{{{ m{M}}_{ m{B}}} - { m{O}}}}))decrease; meanwhile, the transition temperatures of O to MC(({{ m{T}}_{{ m{O}} - {{ m{M}}_{ m{C}}}}}))phase, MCto T(({{ m{T}}_{{{ m{M}}_{ m{C}}} - { m{T}}}}))phase, and T to C (TT–C) phase increase with the increase of DC bias. The phase transformation sequence in the [001]-oriented crystals is R → T → C. As DC bias increases, the transition temperature TR–Tof R to T phase declines and the transition temperature TT–Crises. Intermediate phases MB, O, and MCare only found in the [011]-oriented crystal. The phase transition characteristics of the [011]-oriented crystals are rather more complex than those along [001] direction. The micro–macro domain transition at Tfis related to crystal orientation and DC bias voltage. The phase diagram in terms of temperature and bias voltage is established for [011]- and [001]-oriented 0.24PIN–0.43PMN–0.33PT crystals. The DC bias dependent dielectric properties and phase transition characteristics are also compared with the crystals along [111] direction.