Modeling of the electrostrictive, dielectric, and piezoelectric properties of ceramic PbTiO/sub 3/

The upper and lower limits of the electrostrictive constants, dielectric permittivities, spontaneous polarizations, and piezoelectric coefficients were calculated for ceramic PbTiO/sub 3/ from theoretical single-crystal constants. Experimental ceramic data fall between these upper and lower limits. The large piezoelectric anisotropy d/sub 33//d/sub 31/ of ceramic PbTiO/sub 3/ was shown to be related to the single-crystal PbTiO/sub 3/ electrostrictive anisotropies Q/sub 11//Q/sub 12/ and Q/sub 44//Q/sub 12/. The possibility of a change in sign of the ceramic d/sub 31/ coefficient due to a slight variation in the single-crystal electrostrictive anisotropies was discussed. The single-crystal and predicted ceramic hydrostatic electrostrictive constants were found to be equal. Using this result the ceramic hydrostatic g/sub h/ coefficient is always smaller than the single-crystal g/sub h/, but the ceramic hydrostatic d/sub h/ coefficient can be either larger or smaller than the single-crystal d/sub h/ depending on the dielectric anisotropy ( epsilon /sub 11// epsilon /sub 33/) of the single-crystal.<>