Nagabhushana, B. M. and Chakradhar, R P S and Ramesh, K. P. and Prasad, V. and Shivakumara, C. and Chandrappa, G. T. (2008) Magnetoresistive studies on nanocrystalline La0.8Sr0.2MnO3+delta manganite. Physica B-Condensed Matter, 403 (19-20). pp. 3360-3364. ISSN 0921-4526

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Low-temperature magnetoresistance (MR) measurement has been carried out on nanocrystalline La0.8Sr0.2MnO3+delta manganites prepared by combustion synthesis. This preparation method yields voluminous powders with large surface area (similar to 40 m(2)/g) having crystalline nanosize (similar to 50 nm) products. Formation and homogeneity of the solid solutions have been confirmed by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). Rietveld refinement of X-ray data indicates that as-formed compound exhibits cubic phase with space group Pm3 m. However, calcined sample transforms into rhombohedral phase with space group R-3c. The stabilization of the cubic phase in as-formed manganite is due to the substitution of Sr2+ on La3+ sites, resulting in higher Mn4+ content. The low-temperature resistivity measurements down to 70 K exhibit a broad metal-insulator transition (TM-I) at around 257 K. MR measurements on sintered pellets show similar to 5% MR at 1 T, whereas for 4 and 7 T, the %MR values are found as 22% and 28%. respectively, at TM-I. (C) 2008 Elsevier B.V. All rights reserved.

Item Type: Article
Uncontrolled Keywords: Oxides; Chemical synthesis; X-ray diffraction; Magnetic properties
Subjects: Processing Science
Divisions: Glass
Depositing User: Bula Ghosh
Date Deposited: 19 Jan 2012 12:14
Last Modified: 02 Mar 2012 10:57

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