Electrical properties of Pb2Bi3DyTi5O18 ceramic

Single-phase orthorhombic tungsten bronze (OTB) ceramics, Pb2Bi3DyTi5O18, were prepared by a high-temperature solid-state reaction method. Electrical impedance, phase angle, dielectric constant and dielectric loss were measured in the frequency range 0.1 kHz to 3 MHz at room temperature. The temperature variation of the dielectric constant shows a diffuse phase transition having a diffusivity parameter value of 1.71 at 1 kHz. Pyroelectric current was measured using a direct measurement technique. The temperature dependence of spontaneous polarization was evaluated from the pyroelectric coefficient. The values of the pyroelectric coefficient and spontaneous polarization at room temperature were found, respectively, to be 1.308 x 10(-10) C cm(-2) degreesC(-1) and 1.993 x 10(-7) C cm(-2). The activation energy (E-a = 0.516 eV) was estimated from the temperature variation of the dc resistivity.