The Electrical Characteristics of Nb doped BaTiO3 Ceramics

Abstract

The Nb doped BaTiO3 ceramics, with different Nb2O5 content, ranging from 0.5 to 2.0 at% Nb, were investigated regarding their electrical characteristics in this paper. Nb/BaTiO3 ceramics using in this investigation were prepared by the conventional solid state reaction and sintered at 1320°C in an air atmosphere for 2 hours. The dielectric characteristic of doped BaTiO3 ceramics like as dielectric constant, dissipation factor, impedance (resistance, reactance) have been done by using LCR-Meter Agilent 4284A in the frequency range 20 Hz-1 MHz and Agilent E4991A RF Impedance/Material Analyzer for high frequency measurements (1 MHz – 3 GHz). Dielectric constant and tangent losses after initial large values remains nearly independent of frequency greater than 3 kHz. Dielectric measurements were carried out as a function of temperature up to 180°C. The low doped samples sintered at 1320°C, display the high value of dielectric permittivity at room temperature, 2600 for 0.5Nb/BaTiO3. A nearly flat permittivity-temperature response was obtained in specimens with 2.0 at% additive content. The Curie-Weiss and modified Curie-Weiss law is used to clarify the influence of dopant on the dielectric properties and BaTiO3 phase transformation. All investigated samples have an electrical resistivity ρ >105 Ωcm at room temperature.