Insulator–metal transition and magnetoresistance of oxygen deficient $La_{0.35}Ca_{0.65}MnO_{y}$

Zhao, YG and Fan, R and Zhang, XP and Balci, H and Ogale, SB and Venkatesan, T and Mandal, TK and Gopalakrishnan, J (2004) Insulator–metal transition and magnetoresistance of oxygen deficient $La_{0.35}Ca_{0.65}MnO_{y}$. In: Journal of Magnetism and Magnetic Materials, 284 . pp. 35-42.

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Abstract

The oxygen content of La0.35Ca0.65MnOy was decreased by annealing the samples at high temperatures in vacuum with graphite powder nearby. Insulator metal (I-M) transition occurred upon dramatic decrease of oxygen content. Correspondingly the samples showed a large magnetoresistance (MR) and MR = C(M/M-s)(2) at 4.5 K up to relatively large M/M-s. The results were explained in terms of the variation of Mn3+/Mn4+ ratio and oxygen vacancy ordering induced percolation of the ferromagnetic regions. Spin-dependent hopping model can account for the variation of MR with M/M-s and the variation of C with the decrease of oxygen content.

Item Type:	Journal Article
Publication:	Journal of Magnetism and Magnetic Materials
Publisher:	Elsevier B. V.
Additional Information:	Copyright of this article belongs to Elsevier B. V.
Keywords:	La0.35Ca0.65MnOy;Oxygen content;Insulator–metal transition.
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	19 Dec 2008 05:17
Last Modified:	08 Jan 2013 05:00
URI:	http://eprints.iisc.ac.in/id/eprint/17093

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