Anomalous electrical transport mechanism in ternary carbide Ti0.9Al0.1C above room temperature

The electrical transport properties of ternary carbide Ti0.9Al0.1C prepared by high energy ball milling under argon atmosphere have been reported thoroughly. The samples are characterized by X-ray diffraction technique employing the Rietveld method of structure and microstructure refinement. The dc conductivity of the samples shows semiconducting behavior and it has been analyzed by different existing models. Out of these models the adiabatic small polaron model is most suitable for analyzing the dc conductivity at higher temperature, whereas at lower temperature Schnakenberg acoustical one phonon assisted hopping model is suitable. The dc magnetoconductivity shows a negative variation with magnetic field, which is explained by the theory of wave function shrinkage model. Different parameters like localization length, hopping distance, density of states have been determined from the analysis of the experimental data.