Evolution of ferromagnetism from a frustrated state in LixNi(2-x)O2 (0.67 < x < 0.98)

Sow, Chanchal and Kumar, PS Anil (2013) Evolution of ferromagnetism from a frustrated state in LixNi(2-x)O2 (0.67 < x < 0.98). In: JOURNAL OF PHYSICS-CONDENSED MATTER, 25 (49).

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Abstract

Two-dimensional triangular-lattice antiferromagnetic systems continue to be an interesting area in condensed matter physics and LiNiO2 is one such among them. Here we present a detailed experimental magnetic study of the quasi-stoichiometric LixNi2-xO2 system (0.67<x<0.98). It exhibits a variety of magnetic ground states-namely spin glass, cluster glass, re-entrant spin glass and ferromagnetic. This study deals with the magnetic properties of these four distinct ground states. The spin glass state is evidenced by the frequency-dependent peak shift as well as the time-dependent slow dynamics (magnetic relaxation, magnetic memory effect etc). By tuning the Li deficiency in a controlled manner, an increase in the ordering temperature is observed. Most strikingly, with the Li deficiency the nature of the magnetic ground state is changed from spin glass to ferromagnetic, with two intermediate states-namely cluster glass and re-entrant spin glass. The critical behaviour of the re-entrant spin glass is also studied here. The critical exponents (beta, gamma and delta) are extracted from the modified Arrot plot, Kouvel-Fisher method, and critical isotherm analysis. The critical exponents match with the long-range mean-field model. The values of the critical exponents are confirmed by the Widom scaling law: delta = 1 + gamma beta(-1). Furthermore, the universality class of the scaling relations is verified, where the scaled m and scaled h collapse into two branches. Finally, based on our observations, a phase diagram is constructed.

Item Type:	Journal Article
Publication:	JOURNAL OF PHYSICS-CONDENSED MATTER
Publisher:	IOP PUBLISHING LTD
Additional Information:	copyright for this article belongs to IOP PUBLISHING LTD,ENGLAND
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	18 Dec 2013 05:24
Last Modified:	18 Dec 2013 05:24
URI:	http://eprints.iisc.ac.in/id/eprint/47935

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