Investigation on structural and electrical properties of Co and W modified BaTiO3

Abstract

The influence of co-substitution of Co and W on structural and electrical properties of BaTiO3 (i.e., Ba(Co1/3Ti1/3W1/3)O3) was investigated. This perovskite ceramic was synthesized using a conventional ceramic technology (i.e., high-temperature solid state reaction route, calcination temperature = 1100 °C and sintering temperature = 1200 °C). The compound crystallizes in the orthorhombic phase. The Nyquist plots exhibit the activation of grain boundary effect at 300 °C and the Non-Debye behavior in the sample. The relaxation distribution parameter for the sample at different temperatures is calculated from the depression angle of the semicircular arcs in the Nyquist plot. The activation energy of 0.69 eV estimated for the charge carriers in the grain is almost in good agreement with that of 0.66 eV calculated from the relaxation process of grains. The sample possesses a dielectric constant of 1140 and loss tangent of 0.27 at room temperature which can be exploited for some applications including memory devices, etc. The existence of room temperature hysteresis loop confirms the ferroelectric nature of the sample. On the basis of variation of the exponent in the Jonscher's power law with temperature, correlated barrier hopping is favored as the dominant conduction mechanism in the sample.