Orientation-dependent lattice strains in lead zirconate titanate under mechanical compression by in situ neutron diffraction

Abstract

The electromechanical response of piezoelectric ceramics is a product of the micromechanics of individual grains; a variety of grain orientations with unique responses contribute to the macroscopic bulk ceramic response. In this paper, the lattice strains of tetragonal lead zirconate titanate are measured for many different grain orientations under compressive stress by in situ time-of-flight neutron diffraction. The diffractometer HIPPO at LANSCE is ideal for such orientation-dependent measurements because multiple detector panels measure diffraction vectors oriented throughout the sample orientation space. Parallel to the compression axis at high applied stresses, the 002 lattice strains are larger than the macroscopic strains. Ceramic intergranular stresses prevent each grain from becoming single-domain and less preferred orientations remain.