New Bi(Mg0.75W0.25)O3–PbTiO3 ferroelectric ceramics

An investigation was made into the Bi(Mg0.75W0.25)O3–PbTiO3 (BMW-PT) system. The aim was to find the optimum composition with respect to piezoelectric and dielectric properties and link this to the presence of a morphotropic phase boundary (MPB). The optimum composition was found to be 62 mol% PT. The maximum values of the piezoelectric constant d33 = 150 pm/V and the maximum relative dielectric constant ɛ33/ɛ0 = 1400. The dielectric loss is high with tan δ typically ∼5%. Results from capacity versus the temperature measurements indicate a Curie temperature of 220 °C, which is significantly lower than the predicted value.