Impedance spectroscopy of Na and Nd doped strontium bismuth titanate

Abstract

Sr 0.2 Na 0.4 Nd 0.4 Bi 4 Ti 4 O 15 is prepared by Sol-Gel route using the modified polymeric precursor method based on the Pechini process and its electrical properties are investigated by Complex Impedance Spectroscopy (CIS). Results are presented in two ways, complex plane plots (real versus imaginary) and spectroscopic plots (real and imaginary against frequency). CIS has provided convincing evidence for the existence of both grain (bulk) and grain-boundary effects that were separated in the frequency domain of the impedance spectrum. Experimental data are fitted to two parallel RC equivalent circuits in series. The values of resistance and capacitance of bulk and grain boundary contributions are also calculated. Relaxation times are calculated for both grains and grainboundaries. Conduction and charge carrier behaviors are studied from frequency and temperature dependence of ac conductivity. The ac conductivity follows a two-power law behavior at different temperatures with frequency exponents s 1 and s 2 .

Study of ac impedance spectroscopy of Al doped MnFe2−2xAl2xO4

“…(3) and (4). Such interpretations have also been given earlier [27][28][29] for amorphous chalcogenides. The representation of sample through an electrical analog circuit is very helpful in representing the electrical features of the sample [26].…”

Synthesis and characterization of B-site doped La 0.20 Sr 0.25 Ca 0.45 TiO 3 as SOFC anode materials

“…Such results have been attributed to existence of temperature dependent relaxation with a spread of relaxation times in the material. The relaxation species may possibly be immobile species/electrons at low temperature and defects/vacancies at higher temperatures [16,17]. All the other investigated samples showed similar trend where the resistance decreased with heating showing semi-conducting behavior of the studied compositions.…”

Electrical Properties and AC Conductivity of (Bi0.5Na0.5)0.94Ba0.06TiO3 Ceramic

“…The exponent s 1 (0 ≤ s 1 ≤ 1) characterizes the low-frequency region, corresponding to translational ion hopping and the exponent s 2 (0 < s 2 < 2) characterizes the high-frequency region, indicating the existence of welllocalized relaxation/reorientational process [21], the activation energy of which is ascribed to reorientation ionic hopping. Further, it may be inferred that the slope s 1 is associated with grain-boundary conductivity whereas s 2 depends on grain conductivity [22]. In the jump relaxation model (JRM) introduced by Funke [18] to account for ionic conduction in solids, there is a high probability for a jumping ion to jump back (unsuccessful hop).…”