Processing, texture quality, and piezoelectric properties of 001 _C textured (1-x)Pb(Mg_1/3Nb_2/3)TiO₃ - XPbTiO₃ ceramics

This paper describes the link between texture quality and electromechanical properties for <001>_C textured, 0.03(Na_1/2Bi _1/2)TiO₃ - 0.97[0.715Pb(Mg_1/3Nb _2/3)TiO₃ - 0.285PbTiO₃] (0.03NBT-0.97[PMN-28. 5PT]) ceramics with and without Mn-doping. Here, the subscript C denotes pseudocubic indices. Textured ceramics were prepared by templated grain growth of PMN-25PT on platelet-shaped 0.4(Na_1/2Bi_1/2)TiO ₃-0.6PbTiO₃ (NBT-0.6PT) templates. Texture fractions of f=0.92 (for undoped (1-x)Pb(Mg_1/3Nb_2/3)TiO ₃-xPbTiO₃ (PMN-PT)) and f =0.49 (for Mn-doped PMN-PT) were determined by fitting 002_C XRD pole figures to the March-Dollase model, which was modified to account for symmetry-related 200_C and 020_C reflections. Using resonance methods, the elastic constants c_ij, s_ij, piezoelectric constants d_ij, e _ij, g_ij, h_ij, dielectric constants _ij, and coupling coefficients k_ij of textured PMN-PT ceramics were characterized. It was found that the properties of textured PMN-PT approach the single crystal values along the texture axis (>001< _C, also the poling axis), but not in transverse directions. In particular, the elastic compliance s^E₁₁ (perpendicular to >001<_C) approaches an average of the single crystal s ^E₁₁ and s^E₁₁(45) coefficients, resulting in anomalous -s^E₁₂/s^E₁₁ ratios of - 0.01 and 0.04 in pure and Mn-doped textured PMN-PT, respectively. The 33-mode properties as measured by resonance-antiresonance methods were d₃₃ =852 pC/N, k₃₃=0.83, ε₃₃=3500, and mechanical quality factor Q_m=94 for undoped textured ceramics and d₃₃ =515, k₃₃=0.76, ε₃₃=2200, and Q _m=714 for Mn-doped textured ceramics.