Low temperature studies on normal perovskite oxides: role of correlation and disorder

Raychaudhuri, AK and Rajeev, KP and Srikanth, H and Mahendiran, R (1994) Low temperature studies on normal perovskite oxides: role of correlation and disorder. In: Physica B: Condensed Matter, 197 (1-4). pp. 124-132.

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Abstract

In this report we discuss the main results of low temperature transport and tunneling measurements in correlated metallic oxides belonging to the $ABO_3$ class. Electron-electron interaction in these metallic oxides gives rise to a $T^{1/2}$ term in the conductivity (\sigma) below 10K. The tunneling conductance shows a characteristic cusp. In these materials the metallic state $[\sigma(T = 0)\neq 0]$ is retained for $\sigma(T = 0)< \sigma_{Mott}$ and $d\sigma/dT > 0$. Near the critical region of the metal-insulator transition we find that the conductivity $\sigma(T)$ varies as $\sigma_0 + \alpha T^ m$. However, away from the transition, m = 1/2 and as $\sigma_0 < \sigma_{Mott}$, $m \rightarrow 1/3 \hspace{2mm} or \hspace{2mm} 1/2.5$ depending on the strength of magnetic scattering. But very close to the transition $(\sigma \ll \sigma_{mott}), m \rightarrow 1$.

Item Type:	Journal Article
Publication:	Physica B: Condensed Matter
Publisher:	Elsevier
Additional Information:	Copyright of this article belongs to Elsevier.
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	30 Jun 2008
Last Modified:	19 Sep 2010 04:37
URI:	http://eprints.iisc.ac.in/id/eprint/10744

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