Density of states and spatially inhomogeneous conductance near the metal-insulator transition in $Pr_{0.68}Pb_{0.32}$$MnO_3$ single crystals

Wirth, S and Roessler, Sahana and Ernst, S and Padmanabhan, B and Bhat, HL and Elizabeth, Suja and Steglich, F (2008) Density of states and spatially inhomogeneous conductance near the metal-insulator transition in $Pr_{0.68}Pb_{0.32}$$MnO_3$ single crystals. In: Journal of Physics-Condensed Matter, 20 (43). pp. 434231-1.

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Abstract

Single crystals of $Pr_{0.68}$Pb$_{0.32}$$MnO_3$ have been investigated by scanning tunneling microscopy over a broad temperature range. In this material, a distinct separation of the ferromagnetic and the metal–insulator transition temperature, TC$\approx$210 K and TMI$\approx$255 K, respectively, was observed. Spectroscopic tunneling studies revealed that even on a local scale the system switches from predominantly metallic to insulating within a narrow temperature range around $T_{MI.}$ Inhomogeneities of the zero-bias conductance with small patches of metallic clusters on a length scale of 2–3 nm, however, were only observed within the temperature range TC<T<TMI. The results give direct evidence for phase separation in the paramagnetic metallic state, but homogeneous ferromagnetic and insulating states.

Item Type:	Journal Article
Publication:	Journal of Physics-Condensed Matter
Publisher:	IOP Publishing Ltd
Additional Information:	Copyright for this article belongs to Institute of Physics and IOP Publishing Limited
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	31 Dec 2008 07:17
Last Modified:	19 Sep 2010 04:51
URI:	http://eprints.iisc.ac.in/id/eprint/16398

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