FREQUENCY AND TEMPERATURE DEPENDENCE OF ELECTRICAL PROPERTIES IN PURE AND Nb-DOPED Bi_4TI_3O_(12) CERAMICS

摘要

Pure and Nb-doped Bi4Ti3Oi2 ceramics were prepared by using the conventional solid state reaction method. The dielectric permittivity and electrical modulus in pure and Nb-doped Bi_4Ti_3O_(12) ceramics were measured in the temperature range of 30 approx 700 deg C and the frequency range of 1 Hz approx 1 MHz through an impedance spectroscopy method. The obtained results showed well-defined relaxation peaks. The conductivity relaxation times are determined from the peaks of the modulus. The activation energies associated with hopping condition are 0.42 eV and 0.53 eV in pure and Nb-doped Bi4Ti3O12 ceramics, respectively.