Singh, Vijeta and Pulikkotil, J. J. (2016) Electronic phase transition and transport properties of Ti2O3. Journal of Alloys and Compounds, 658. 430-434 . ISSN 0925-8388

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Abstract

There exists several inconsistencies between the experimental results and theoretical band structure calculations for Ti2O3. While the local approximations describing the exchange correlation potential of the crystal Hamiltonian completely fails to describe the metal-insulator transition, the hybrid functionals and the Hartree-Fock method tends to overestimate the materials band gap. In this work, we report the physical properties of Ti2O3 using the modified Becke-Johnson exchange correlation potential. The approach not only captures the metal-insulator transition as a function of increasing Ti-Ti bond distance, but also reasonably predicts the magnitude of the materials band gap. The distribution of electronic states is consistent with the Van Zandt-Honig-Goodenough model which attributes to the electronic repulsion between the bonding and antibonding states of the otherwise split t(2g) bands of Ti 3d manifold, in a rhombohedral field. Transport properties calculated using the Boltzmann transport equation in the constant relaxation time approximation clearly reveals the semi-metallic characteristics of Ti2O3. The Seebeck coefficient, calculated as high as > 400 mu V/K at similar or equal to T = 140 K infers that the material can be used as a potential low temperature oxide thermoelectric.

Item Type:	Article
Additional Information:	Copyright for this article belongs to M/s Elsevier.
Uncontrolled Keywords:	Density functional theory Semi-metals Boltzmann transport theory
Subjects:	Chemistry > Physical Chemistry Materials Science Metallurgy & Metallurgical Engineering
Divisions:	UNSPECIFIED
Depositing User:	Dr. Rajpal Walke
Date Deposited:	17 Nov 2017 11:23
Last Modified:	17 Nov 2017 11:23
URI:	http://npl.csircentral.net/id/eprint/2201

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