Diffuse ferroelectric phase transition and cation order in the solid solution system Pb(Sc_1/2Nb_1/2)O₃:Pb(Sc_1/2Ta_1/2)O₃

Abstract

Earlier studies^1-3 have shown that in Pb(Sc_1/2Ta_1/2)O₃ PST and Pb(Sc_1/2Nb_1/2)O₃ which are simple cubic perovskites, the degree of ordering of the different B site cations in the ABO₃ structure can be controlled thermally. Quenched disordered crystals and ceramics show diffuse dispersive dielectric properties, while well annealed ordered materials exhibit “normal” sharp first order transitions. In this work the solid solutions between PST and PSN are shown to permit control of both the centroid and the span of the diffuse Curie range. Since the depolarization curve can be modified by both composition and cation ordering, interesting pyroelectric effects are possible.