Abstract
The direct and alternating current electrical conductivities of lanthanum chromite ceramic doped with 1 to 3 wt% TiO2 have been measured at temperatures from 20 to 200° C. The sample containing 3 wt% TiO2 has been studied in detail because of all the samples it showed the highest sintered density and electrical conductivity. Alternating current conductivity, σ ac, measurements taken over the frequency range 10 kHz to 1 MHz were found to follow a power law of the form σ ac ∝ ω n, where ω is the frequency and 0.5<n<1, indicative of a hopping conduction mechanism. In addition, a dispersion in the dielectric constant was observed. The dispersion peak frequency has been found to be thermally activated with an activation energy of 0.423±0.002 eV. The results are successfully interpreted in terms of a model proposed by Pike, wherein a classical hopping of charge carriers (over a potential barrier) between the localized states is considered. The direct current conductivity activation energy predicted from this model is found to be consistent with the experimentally obtained value.
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Bansal, K.P., Kumari, S., Das, B.K. et al. Electrical conduction in titania-doped lanthanum chromite ceramics. J Mater Sci 16, 1994–1998 (1981). https://doi.org/10.1007/BF00540648
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DOI: https://doi.org/10.1007/BF00540648