Effective electromechanical moduli of ferroelectric ceramics with fiber textures

In this letter, we report the predictions on the effective piezoelectric coefficients and electromechanical coupling factors of ferroelectric ceramics BaTiO 3 and Pb(Mg 1/3Nb 2/3)O 3–PbTiO 3 (PMN-PT) with various fiber textures, including [001], [011], and [111], using a two-scale micromechanical model that accounts for microstructural phenomena at both domain and grain levels. It was observed that for BaTiO 3 the [011] texture is optimal with highest d 31 and d 33, while for PMN-PT [001] texture is optimal despite the fact that [011]-oriented single-crystalline PMN-PT has higher d 32 than that of [001]-oriented PMN-PT single crystal. In fact, [011]-textured PMN-PT ceramics have much smaller piezoelectric coefficients d 32 and d 33 than does [011]-oriented PMN-PT single crystal. It is also noted that [001]-textured BaTiO 3 and PMN-PT ceramics have even higher electromechanical coupling factor k 31 than that of [001]-oriented single crystals