A modified Rietveld method to model highly anisotropic ceramics

作者：Tutuncu G^*; Motahari M; Daymond M R; Ustundag E

来源：Acta Materialia, 2012, 60(4): 1494-1502.

DOI：10.1016/j.actamat.2011.11.050

• Piezoelectricity
• X-ray diffraction
• Rietveld

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%26apos;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.

• 出版日期2012-2