Prof. María Elena Villafuerte-Castrejón is invited at 2016 ICDD Spring Meetings 14-18 March 2016 – ICDD Headquarters. Newtown Square, Philadelphia (PA), USA and contributes with the work on “Multi-symmetric structure of (1-x)(Bi0.5Na0.5)TiO3-x(Ba0.9Ca0.1)TiO3 ceramics” by M. E. Villafuerte-Castrejón, R. Vivar-Ocampo, A. M. González and L Pardo.
The works on structural determination by X-ray on poled ceramics at the MPB composition of the system (1-x)(Bi0.5Na0.5)TiO3-xBaTiO3 (x=0.06) claim that there is rhombohedral and tetragonal symmetries coexistence. However, the expected increase of the piezoelectric properties has not been reported. As an alternative to explain this discrepancy, an structural model of a major, rhombohedral (ferroelectric), symmetry accompanied by a weakly polar pseudocubic one has been proposed from high resolution X-ray diffraction (XRD) with synchrotron radiation and full-pattern Rietveld analysis. To study the structure at the MPB of this type of compositions, we have processed by Pechini route ceramics of 0.94(Bi0.5Na0.5)TiO3-0.06(Ba0.9Ca0.1)TiO3, searching for a MPB composition to enlighten on the crystal structure issue. Ceramic were studied by conventional (Cu-Kα radiation) X-ray diffraction.
