Temperature-Dependent Phase Transition in Orthorhombic [011]_c Pb(Mg_1/3Nb_2/3) O₃-0.35PbTiO₃ Single Crystal

Relaxor [011]_c PMN-0.35PT single crystal phase transition characteristics are investigated through various methods including variable temperature dielectric properties, X-ray diffraction, bipolar ferroelectric hysteresis loops (P-E) and electric-field-induced strain (S-E) hysteresis loops measurements. The results reveal that two phase transitions exist within the range from room temperature to 250 °C: orthorhombic (O)-tetragonal (T)-cubic (C). The O-to-T and T-to-C phase transition temperatures have been identified as 84 °C and 152 °C, respectively. Diffuseness degree of the T-to-C phase transition for the unpoled single crystal has been calculated to be 1.56, implying an intermediate state between normal and relaxor ferroelectrics. Temperature-dependent remanent polarization (P_r), coercive field (E_c), saturation polarization (P_s), hysteresis loop squareness (R_sq), and longitudinal piezoelectric constant (d* 33) are also explored to learn the details of the phase transitions. Variable temperature unipolar S_uni-E hysteresis loops avail additional evidence for the microstructure change in the as-measured single crystal. View Full-Text