Crystal structure and thermal and electrical properties of the perovskite solid solution Nd1-xSrxFeO3-delta (0 <= x <= 0.4)

Dasgupta, Niladri and Krishnamoorthy, R and Jacob, Thomas K (2002) Crystal structure and thermal and electrical properties of the perovskite solid solution Nd1-xSrxFeO3-delta (0 <= x <= 0.4). In: Solid State Ionics, 149 (3-4). pp. 227-236.

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Abstract

The crystal structure, thermal expansion and electrical conductivity of strontium-doped neodymium ferrite (Nd1-xSrxFeO3-delta where 0less than or equal toxless than or equal to0.4) were investigated. All compositions had the GdFeO3-type orthorhombic perovskite structure. The lattice parameters were determined at room temperature by X-ray powder diffraction. The orthorhombic distortion decreases with increasing Sr substitution. The pseudocubic lattice parameter shows a minimum at x=0.3. The thermal expansion curves for x=0.2-0.4 displayed rapid increase in slope at higher temperatures. The electrical conductivity increased with Sr content and temperature. The calculated activation energies for electrical conduction decreased with increasing x. The electrical conductivity can be described by the small polaron hopping mechanism. The charge compensation for divalent ion on the A-site is provided by the formation of Fe4+ ions on the B site and vacancies on the oxygen sublattice. The results indicate two defect domains: for low values of x, the predominant defect is Fe4+ ions, whereas for higher values of x, oxygen vacancies dominate. (C) 2002 Elsevier Science B.V. All rights reserved.

Item Type:	Journal Article
Publication:	Solid State Ionics
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Keywords:	Perovskite solid solution;Crystal structure;Thermal expansion;Electrical conductivity;Defects
Department/Centre:	Division of Chemical Sciences > Materials Research Centre Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	21 Jul 2011 07:42
Last Modified:	21 Jul 2011 07:42
URI:	http://eprints.iisc.ac.in/id/eprint/39128

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