ISSN:
1573-4803
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
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.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00540648
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