Study of electrical and dielectric properties of Y2O3 doped Ba1 − x(Bi0.5Na0.5)xTiO3 ceramics

Y2O3-doped Ba1 − x(Bi0.5Na0.5)xTiO3 ceramics were prepared by a conventional mixed oxide method. The XRD results showed that the phase compositions of all samples were pure tetragonal phases and the tetragonality c/a of the perovskite lattice varied with the Y2O3 and NBT contents. In order to study the electrical properties of (1-y)Ba1 − x(Bi0.5Na0.5)xTiO3-yY2O3 ceramics, we used the Cole–Cole plot, that is, the graphic of Y′ versus Y″. The results showed that a single semicircular arc appeared and its radii of curvature firstly decreased and then increased with the increase of NBT and Y2O3 contents. In addition, the relative permittivity and dielectric loss versus frequency were characterized in the frequency range of 100 Hz–2 MHz. It can be found that relative permittivity and dielectric loss regularly changed with the increase of Y2O3 and NBT contents.

► The phase compositions of all samples were pure tetragonal phases.
► Relative permittivity firstly increased and then decreased with increasing of NBT.
► Relative permittivity firstly decreased and then increased with increasing of Y2O3.
► A single semicircular arc appeared in the Cole–Cole plot.
► Radii of curvature showed regular changed with increasing of NBT and Y2O3.