Dielectric and electromechanical properties of barium titanate single crystals grown by templated grain growth

Single crystals of BaTiO/sub 3/ were grown by templated grain growth (TGG). TGG involves contacting a single crystal "template" to a sintered polycrystalline matrix, then heating the assemblage to a temperature that promotes the migration of the single crystal boundary through the matrix. In this investigation the properties of millimeter-sized, plate-shaped and bar-shaped, single crystals of BaTiO/sub 3/ grown by TGG were examined in order to compare the results to single crystals grown by conventional methods. A dielectric constant, /spl epsi//sub 33//sup T///spl epsi//sub 0/, of 260, polarizations of P/sub R//spl sim/16 /spl mu/C/cm/sup 2/ and P/sub sat//spl sim/21.5 /spl mu/C/cm/sup 2/, electromechanical coupling coefficients of k/sub 33//spl sim/0.51 and k/sub 31//spl sim/0.18, and a piezoelectric coefficient of d/sub 33//spl sim/140 pC/N were achieved. Entrapped porosity in the crystals made fully poling the crystals difficult.