Local structure and magneto-transport in $Sr_2FeMoO_6$ oxides

Liscio, F and Bardelli, F and Meneghini, C and Mobilio, S and Ray, Sugata and Sarma, DD (2006) Local structure and magneto-transport in $Sr_2FeMoO_6$ oxides. In: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 246 (1). pp. 189-193.

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Abstract

Double perovskite oxides $Sr_2FeMoO_6$ have attracted a great interest for their peculiar magneto-transport properties, and, in particular, for the large values of low-field magneto-resistance (MR) which remains elevated even at room temperature, thanks to their high Curie temperature ($T_ c$> 400 K). These properties are strongly influenced by chemical cation disorder, that is by the relative arrangement of Fe and Mo on their sublattices: the regular alternation of Fe and Mo enhances the MR and saturation magnetization. On the contrary the disorder generally depresses the magnetization and worsen the MR response. In this work the X-ray absorption fine structure (XAFS) technique has been employed in order to probe the cation order from a local point of view. XAFS spectra were collected at the Fe and Mo K edges on $Sr_2FeMoO_6$ samples with different degree of long-range chemical order. The XAFS results prove that a high degree of short-range cation order is preserved, despite the different long-range order: the Fe–Mo correlations are always preferred over the Fe–Fe and Mo–Mo ones in the perfectly ordered as well as in highly disordered samples.

Item Type:	Journal Article
Publication:	Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
Publisher:	Elsevier
Additional Information:	Copyright of this article belongs to Elsevier.
Keywords:	Double-perovskites;XAFS;Structure
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	16 May 2006
Last Modified:	19 Sep 2010 04:26
URI:	http://eprints.iisc.ac.in/id/eprint/6681

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