J. Anthoniappen, C.S. Tu, P.-Y. Chen, C.-S. Chen, S.-J. Chiu, H.-Y. Lee, Yi Ting, S.-F. Wang, C.-K. Chai
Structure, phase transition, and dielectric relaxor behavior have been investigated in morphotropic phase boundary compositions of (1 - x)(Bi0.5Na0.5)TiO3-xBaTiO3ceramics for x = 0.06, 0.07, and 0.075. In-situ structural thermal stability has been analyzed by using high-resolution synchrotron X-ray diffraction as a function of temperature. A transition sequence of rhombohedral + tetragonal - tetragonal - cubic phases is observed upon heating. The "rhombohedral + tetragonal" indicates a coexistence of rhombohedral R3c and tetragonal P4bm phases. The two-phase coexistence extends from room temperature to 200 °C. Zero-field dielectric permittivity reveals a frequency dispersion at low temperature region (T < Tm) and polar nanoregions below Burns temperature (TB). The two-phase coexistence plays a vital role for frequency dispersion below Tm. Dielectric spectra of pre-poled samples reveal a field-induced ferroelectric-relaxor phase transition at depolarization temperature Td. © 2014 Elsevier B.V. All rights reserved.
Graduate Institute of Applied Science and Engineering, Fu Jen Catholic University, New Taipei City, 24205, Taiwan; Department of Physics, University of San Carlos, Cebu City, 6000, Philippines; Department of Physics, Fu Jen Catholic University, New Taipei City, 24205, Taiwan; Department of Mechanical Engineering, Ming-Chi University of Technology, New Taipei City, 24301, Taiwan; Department of Mechanical Engineering, Hwa-Hsia Institute of Technology, New Taipei City, 23567, Taiwan; National Synchrotron Radiation Research Center, Hsinchu, 30076, Taiwan
