Electrical transport properties of $LaNi_1_-_xM_xO_3$ (M = Co, Mn) thin films fabricated by pulsed laser deposition

Lekshmi, Chaitanya I and Gayen, Arup and Hegde, MS (2005) Electrical transport properties of $LaNi_1_-_xM_xO_3$ (M = Co, Mn) thin films fabricated by pulsed laser deposition. In: Journal Of Physis:Condensed Matter, 17 (41). pp. 6445-6458.

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Abstract

Highly oriented thin films of $LaNi_1_-_xM_xO_3$ (M = Mn, Co) are grown on $LaAlO_3(100)$ substrate by pulsed laser deposition. They undergo a metal to insulator transition when the Mn or Co concentration is increased. The observed conduction pattern is highly sensitive to the doping concentration in these thin films. The conduction pattern also varies as the doping element is varied from Mn to Co. There is a large dominance of electron–lattice interactions in the conduction mechanism of the charge carriers. While the metallic thin films of $LaNi_1_-_xCo_xO_3$ show a linear variation of resistivity with temperature, $LaNi_1_-_xMn_xO_3$ thin films exhibit a prominent square-root dependence of resistivity on temperature. At high concentrations of Mn or Co, the conduction takes place via a polaron hopping mechanism, which suggests that lattice polarization may be present in these films. The change observed in the transport properties is attributed to the charge disproportionation between the $Ni^3^+–Ni^2^+$ pairs, which are favoured more in Mn doped thin films. The photoelectron spectroscopic studies give evidence of charge disproportionation present in these films.

Item Type:	Journal Article
Publication:	Journal Of Physis:Condensed Matter
Publisher:	Institute of Physics
Additional Information:	Copyright of this article belongs to Institute of Physics.
Keywords:	Forests;Subgraphs;Degree conditions
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	30 Apr 2007
Last Modified:	19 Sep 2010 04:37
URI:	http://eprints.iisc.ac.in/id/eprint/10771

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