A modified Rietveld method to model highly anisotropic ceramics


Tutuncu G., Motahari M., DAYMOND M. R. , Ustundag E.

ACTA MATERIALIA, cilt.60, ss.1494-1502, 2012 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 60 Konu: 4
  • Basım Tarihi: 2012
  • Doi Numarası: 10.1016/j.actamat.2011.11.050
  • Dergi Adı: ACTA MATERIALIA
  • Sayfa Sayıları: ss.1494-1502

Özet

High energy X-ray diffraction was employed to probe the complex constitutive behavior of a polycrystalline ferroelectric material in various sample orientations. Pb(Zn,Nb)O-3-Pb(Zr,Ti)O-3 (PZN-PZT) ceramics were subjected to a cyclic bipolar electric field while diffraction patterns were taken. Using transmission geometry and a two-dimensional detector, lattice strain and texture evolution (domain switching) were measured in multiple sample directions simultaneously. In addition, texture analysis suggests that non-180 degrees domain switching is coupled with lattice strain evolution during uniaxial electrical loading. As a result of this material's high strain anisotropy, the full-pattern Rietveld method was inadequate to analyze the diffraction data. Instead, a modified Rietveld method, which includes an elastic anisotropy term, yielded significant improvements in the data analysis results. (C) 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.