Interface-induced spontaneous positive and conventional negative exchange bias effects in bilayer La0.7Sr0.3MnO3/Eu0.45Sr0.55MnO3 heterostructures

Murthy, J Krishna and Kumar, P S Anil (2017) Interface-induced spontaneous positive and conventional negative exchange bias effects in bilayer La0.7Sr0.3MnO3/Eu0.45Sr0.55MnO3 heterostructures. In: SCIENTIFIC REPORTS, 7 .

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Abstract

We report zero-field-cooled spontaneous-positive and field-cooled conventional-negative exchange bias effects in epitaxial bilayer composed of La0.7Sr0.3MnO3 (LSMO) with ferromagnetic (FM) and Eu0.45Sr0.55MnO3 (ESMO) with A-type antiferromagnetic (AF) heterostructures respectively. A temperature dependent magnetization study of LSMO/ESMO bilayers grown on SrTiO3 (001) manifest FM ordering (T-C) of LSMO at similar to 320 K, charge/orbital ordering of ESMO at similar to 194 K and AF ordering (T-N) of ESMO at similar to 150 K. The random field Ising model has demonstrated an interesting observation of inverse dependence of exchange bias effect on AF layer thickness due to the competition between FM-AF interface coupling and AF domain wall energy. The isothermally field induced unidirectional exchange anisotropy formed at the interface of FM-LSMO layer and the kinetically phase-arrested magnetic phase obtained from the metamagnetic AF-ESMO layer could be responsible for the spontaneous exchange bias effect. Importantly, no magnetic poling is needed, as necessary for the applications. The FM-AF interface exchange interaction has been ascribed to the AF coupling with Sigma J(ex)(S) over arrow(FM) .(S) over arrow(AF) (J(ex) approximate to J(AF), coupling constant between AF spins) for the spontaneous positive hysteresis loop shift, and the field-cooled conventional exchange bias has been attributed to the ferromagnetically exchanged interface with J(ex) approximate to J(F) (coupling constant between FM spins).

Item Type:	Journal Article
Publication:	SCIENTIFIC REPORTS
Additional Information:	Copy right for this article belongs to the NATURE PUBLISHING GROUP, MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	11 Nov 2017 06:53
Last Modified:	11 Nov 2017 06:53
URI:	http://eprints.iisc.ac.in/id/eprint/58221

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