Immittance Studies of BiFeTiO Ceramics.

Results of studies focusing on the electric behavior of BiFeTiO (BFTO) ceramics are reported. BFTO ceramics were fabricated by solid state reaction methods. The simple oxides BiO, TiO, and FeO were used as starting materials. Immittance spectroscopy was chosen as a method to characterize electric and dielectric properties of polycrystalline ceramics. The experimental data were measured in the frequency range Δ = (10-10) Hz and the temperature range Δ = (-120-200) °C. Analysis of immittance data was performed in terms of complex impedance, electric modulus function, and conductivity. The activation energy corresponding to a non-Debye type of relaxation was found to be = 0.573 eV, whereas the activation energy of conductivity relaxation frequency was found to be = 0.570 eV. An assumption of a hopping conductivity mechanism for BFTO ceramics was studied by 'universal' Jonscher's law. A value of the exponents was found to be within the "Jonscher's range" (0.54 ≤ ≤ 0.72). The -conductivity was extracted from the measurements. Activation energy for -conductivity was calculated to be = 0.78 eV, whereas the hopping activation energy was found to be = 0.63 eV. The obtained results were discussed in terms of the jump relaxation model.