Roy, Amritendu and Prasad, Rajendra and Auluck, Sushil and Garg, Ashish (2012) Effect of site-disorder on magnetism and magneto-structural coupling ingallium ferrite: A first-principles study. Journal of Applied Physics , 111. 043915-1. ISSN 0021-8979

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Abstract

We report a first-principles study of the magnetic properties, cation site disorder effect onmagnetism and magneto-structural coupling in multiferroic gallium ferrite (GFO) using the localspin density approximation (LSDAþU) of the density functional theory. The calculation of theground state A-type antiferromagnetic structure predicts magnetic moments consistent with theexperiments while consideration of spin-orbit coupling yields a net orbital moment also in goodaccordance with the experiment. We find that though cation site disorder is not spontaneous in theground state, interchange between octahedrally coordinated Fe2 and Ga2 sites is most favored inthe disordered state. The results show that ferrimagnetism in GFO is primarily due to Ga-Fesite disorder such that Fe spins at Ga1 and Ga2 sites are antiferromagnetically aligned whilemaintaining ferromagnetic coupling between Fe spins at Ga1 and Fe1 sites as well as between Fespins at Ga2 and Fe2 sites. Thus we are able to explain the origin of ferrimagnetism in GFO basedon cation site disorder. Our calculations, further predict the presence of magneto-structural couplingin GFO which has been recently observed experimentally.

Item Type:	Article
Additional Information:	Copyright for this article belongs to M/s American Institute of Physics.
Subjects:	Materials Science Applied Physics/Condensed Matter
Divisions:	UNSPECIFIED
Depositing User:	Users 27 not found.
Date Deposited:	20 Feb 2020 11:30
Last Modified:	20 Feb 2020 11:30
URI:	http://npl.csircentral.net/id/eprint/3618

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