Core/shell structure in Pb(Mg1/3Nb2/3)O3-PbTiO3

Law-temperature hot-pressed Pb(Mg1/3Nb2/3)O-3 (PMN)-PbTiO3(PT) materials exhibited a small temperature dependence of dielectric constants. The microstructure was studied by means of a transmission electron microscope (TEM). It was found that a core/shell structure with a pure PMN core and a PMN-PT shell was formed in the majority of grains. The small temperature dependence of dielectric constants was attributed to the existence of the core/shell structure. It was also found that the core/shell structure was formed at the early stage of hot-pressing and that diffusion of Ti was suppressed under pressure once the material became dense.