Temperature dependence of density of states near the Fermi level in a strain-free epitaxial film of the hole-doped manganite La0.7Ca0.3MnO3

Mitra, J. ; Paranjape, Mandar ; Raychaudhuri, A. K. ; Mathur, N. D. ; Blamire, M. G. (2005) Temperature dependence of density of states near the Fermi level in a strain-free epitaxial film of the hole-doped manganite La0.7Ca0.3MnO3 Physical Review B: Condensed Matter and Materials Physics, 71 (9). 094426_1-094426_8. ISSN 1098-0121

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Official URL: http://prb.aps.org/abstract/PRB/v71/i9/e094426

Related URL: http://dx.doi.org/10.1103/PhysRevB.71.094426

Abstract

Scanning tunneling spectroscopy measurements were performed on an epitaxial thin film of La0.7Ca0.3MnO3 grown on a NdGaO3 substrate. The temperature variation of the density of states (DOS) close to the ferromagnetic transition temperature (Tc) was investigated. The strain-free film exhibiting a sharp metal-insulator transition at Tp≈Tc≈268 K shows no phase separation as seen by the conductivity map, allowing unambiguous determination of the tunneling spectra as a function of T. The temperature dependence of the conductance (dI/dV) curves and the normalized DOS clearly indicate a depletion in DOS near Tc, which fills up as the sample is cooled below Tc. The metal-insulator transition at Tc also shows up in the bias dependence of the tunneling curve as the temperature is changed across the transition. In the metallic phase we find that the DOS is similar to what is expected in a correlated metal.

Item Type:Article
Source:Copyright of this article belongs to The American Physical Society.
ID Code:42680
Deposited On:06 Jun 2011 05:28
Last Modified:17 May 2016 23:53

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