Anomalous variation of magnetoresistance in $Nd_{0.67-y}Eu_ySr_{0.33}Mn_{03}$ manganites

Venkataiah, G and Prasad, V and Reddy, Venugopal P (2007) Anomalous variation of magnetoresistance in $Nd_{0.67-y}Eu_ySr_{0.33}Mn_{03}$ manganites. In: Solid State Communications, 141 (2). pp. 73-78.

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Abstract

A systematic investigation of Eu-doped Nd-based colossal magnetoresistive manganites with compositional formula $Nd_{0.67-y}Eu_ySr_{0.33}Mn_{03}$ (y = 0–0.67) has been undertaken to understand their structural, magnetic as well as electrical behavior. These materials were prepared by the citrate gel route, and were later characterized by X-ray diffraction (XRD), AC susceptibility, electrical resistivity etc; measurements. A detailed structural characterization of the XRD data has also been undertaken, using Rietveld refinement method. From a systematic analysis of electrical resistivity versus temperature data, it has been found that the last two samples of the series (y = 0.57 and 0.67) are found to exhibit charge order (CO) phenomenona, and that the CO state melts completely in the case of former sample (y = 0.57) while it melts partially only in the case of later one (y = 0.67), even in a magnetic field of 7 T. The observed behavior has been explained qualitatively. Some of the samples of the series are found to exhibit unusually large magnetoresistance over a wide temperature range in the low temperature region, and their behavior has been explained on the basis of phase segregation and an inter-grain spin polarized tunneling effect.

Item Type:	Journal Article
Additional Information:	Copyright of this article belongs to Elsevier.
Keywords:	Manganite;Sol–gel technique;Grain boundary;Magnetoresistance
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	23 Jan 2007
Last Modified:	19 Sep 2010 04:34
URI:	http://eprints.iisc.ernet.in/id/eprint/9588

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