Critical behavior of multiferroic sulpho spinel compounds: MCr2S4 (M = Co & Fe)

Dey, K and Indra, A and Giri, S (2017) Critical behavior of multiferroic sulpho spinel compounds: MCr2S4 (M = Co & Fe). In: JOURNAL OF ALLOYS AND COMPOUNDS, 726 . pp. 74-80.

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Abstract

Near the param agnetic to ferrim agnetic transition tem perature, the dc magnetization data of two sulphospinels, CoCr2S4 and FeCr2S4, are analyzed by the modified Arrott plot, the Kouvel-Fisher method, log Mvs log H, and the scaling analysis. Critical exponents beta = 0.3946 +/- 0.0064, 0.421 +/- 0.04, gamma = 1.101 +/- 0.004,1.041 +/- 0.015, and delta = 3.77 +/- 0.06, 3.512 +/- 0.14 are obtained around the critical tem perature similar to 224.4 K and 166.5 K for CoCr2S4 and FeCr2S4, respectively. Scaling analysis indicates that calculated critical exponents,as well as critical temperatures, are intrinsic to the systems. The values of critical exponents of CoCr2S4 are between those predicted for a three dimensional Heisenberg m odel and those predicted by meanfield theory. Probably, the observed large spin-phonon coupling and magnetocrystalline anisotropy caused by Co ion may play the key role in this critical behavior of CoCr2S4. The critical exponents of FeCr2S4 are close to the mean field theory except for &delta, which is higher than the theoretical value. The higher value of delta may arise due to the incom plete ferrim agnetic transition and presence of short rangem agnetic ordering above T-c for FeCr2S4. (C) 2017 Elsevier B.V. All rights reserved.

Item Type:	Journal Article
Publication:	JOURNAL OF ALLOYS AND COMPOUNDS
Additional Information:	Copy right for this article belongs to the ELSEVIER SCIENCE SA, PO BOX 564, 1001 LAUSANNE, SWITZERLAND
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	03 Nov 2017 10:54
Last Modified:	03 Nov 2017 10:54
URI:	http://eprints.iisc.ac.in/id/eprint/58136

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