IMPROVED DIELECTRIC AND PIEZOELECTRIC PROPERTIES OF Pb(Mg{sub}(1/3),Nb{sub}(2/3))O{sub}3-32.5PbTiO{sub}3 CERAMICS AND 001 TEXTURED PMN-PT

摘要

Ceramic samples of the morphotropic phase boundary (MPB) composition of (1-x)Pb(Mg{sub}(1/3),Nb{sub}(2/3))O{sub}3-xPbTiO{sub}3 (x=0.32) were prepared by the columbite precursor method with no excess PbO used for densification. Samples were sintered in air and oxygen, respectively to study the effect of these two different processing conditions on the sintering process. The oxygen-sintered samples densified quickly. The high density and absence of excess PbO, coupled with sintering of samples in oxygen resulted in excellent dielectric, ferroelectric and piezoelectric properties. A maximum dielectric constant of ～41,500 and a maximum strain of ～0.17 % at ～30 kV/cm, associated with a piezoelectric constant (d{sub}33) of 785 pC/N were recorded on the samples having the highest density. High quality <001> textured PMN-PT was produced using tabular SrTiO{sub}3 particles. For these materials, the best properties were a piezoelectric coefficient of 1200 pC/N upto 10kV/cm and a strain of 0.32 % at 50 kV/cm.