Phase transition and chemical order in the ferroelectric perovskite (1-x) Bi (Mg34 W14) O3 -xPbTi O3 solid solution system

Building on the ferroelectric family based on the Bi (Me+3) O3 -PbTi O3 solid solutions, the complex solid solution (1-x) Bi (Mg34 W14) O3 -xPbTi O3 [(1-x) BMW-xPT] was investigated. This system was found to exhibit a broad morphotropic phase boundary at x~0.48 mol % PbTi O3 with a corresponding Curie temperature of 205 °C separating pseudocubic and tetragonal ferroelectric phases. Based on dielectric, x-ray diffraction (XRD), and calorimetric data, a simple dielectric phase field diagram was established. On further structural analysis with diffraction contrast transmission electron microscopy along with XRD, evidence of B-site chemical ordering was found for the (1-x) Bi (Me′ Me″) O3 -xPbTi O3 perovskite family.