Charge ordering and antiferromagnetic transitions in $Nd_xCa_{1-x}MnO_3(x = 0.2, 0.3)$ manganites

Joshi, Janhavi P and Bhagwat, Amar R and Sarangi, Subhasis and Sharma, Ajay and Bhat, SV (2004) Charge ordering and antiferromagnetic transitions in $Nd_xCa_{1-x}MnO_3(x = 0.2, 0.3)$ manganites. In: Physica B: Condensed Matter, 349 (1-4). pp. 35-43.

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Abstract

In this paper we present transport, magnetic and electron paramagnetic resonance (EPR) studies of electron doped manganites $Nd_xCa_{1-x}MnO_3(x = 0.2, 0.3)$ with a view to compare and contrast their properties with those of the hole doped $Nd_{0.5}Ca_{0.5}MnO_3$ and other manganites. The samples were prepared by the solid-state reaction method and the composition was verified using X-ray and EDAX measurements. Magnetization measurements on the x = 0.2 sample (NCMO 0.2) show a peak at 155 K accompanied by a sharp increase in the resistivity. In the case of x = 0.3 sample (NCMO 0.3) a peak in the magnetization along with an increase in the resistivity is observed at 220 K. From a comparison of the EPR results in the two compounds, we conclude that the transition in NCMO 0.2 is an antiferromagnetic transition which is likely to be a charge ordering transition as well and that in NCMO 0.3 is only a charge ordering transition at which long-range magnetic order is not established. We infer that in this compound the long-range antiferromagnetic order sets in at a much lower temperature below which the EPR signal disappears due to the opening of an antiferromagnetic gap.

Item Type:	Journal Article
Additional Information:	The copyright belongs to Elsevier.
Keywords:	Electron paramagnetic resonance;Rare earth manganites;Charge ordering transition;Antiferromagnetic transition
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	02 May 2006
Last Modified:	19 Sep 2010 04:26
URI:	http://eprints.iisc.ernet.in/id/eprint/6533

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