Site-Resolved Contributions to the Magnetic-Anisotropy Energy and Complex Spin Structure of Fe/MgO Sandwiches
Cuadrado, Ramón (Institut Català de Nanociència i Nanotecnologia)
Oroszlány, László (Eötvös University. Department of Physics of Complex Systems)
Deák, András (Budapest University of Technology and Economics. Department of Theoretical Physics)
Ostler, Thomas A. (Université de Liège. Department of Physics)
Meo, Andrea (University of York. Department of Physics)
Chepulskii, Roman V. (Samsung Electronics)
Apalkov, Dmytro (Samsung Electronics)
Evans, Richard F. L. (University of York. Department of Physics)
Szunyogh, László (Budapest University of Technology and Economics)
Chantrell, Roy W. (University of York. Department of Physics)

Fecha:	2018
Resumen:	Fe/MgO-based magnetic tunnel junctions are among the most promising candidates for spintronic devices due to their high thermal stability and high tunneling magnetoresistance. Despite its apparent simplicity, the nature of the interactions between the Fe and MgO layers leads to complex finite-size effects and temperature-dependent magnetic properties which must be carefully controlled for practical applications. In this article, we investigate the electronic, structural, and magnetic properties of MgO/Fe/MgO sandwiches using first-principles calculations and atomistic spin modeling based on a fully parametrized spin Hamiltonian. We find a large contribution to the effective interfacial magnetic anisotropy from the two-ion exchange energy. Minimization of the total energy using atomistic simulations shows a surprising spin-spiral ground-state structure at the interface owing to frustrated ferromagnetic and antiferromagnetic interactions, leading to a reduced Curie temperature and strong layerwise temperature dependence of the magnetization. The different temperature dependences of the interface and bulklike layers results in an unexpected nonmonotonic temperature variation of the effective magnetic-anisotropy energy and temperature-induced spin-reorientation transition to an in-plane magnetization at low temperatures. Our results demonstrate the intrinsic physical complexity of the pure Fe/MgO interface and the role of elevated temperatures providing insight when interpreting experimental data of nanoscale magnetic tunnel junctions.
Ayudas:	European Commission 281043 Ministerio de Economía y Competitividad SEV-2013-0295 European Commission 665919
Derechos:	Tots els drets reservats.
Lengua:	Anglès
Documento:	Article ; recerca ; Versió acceptada per publicar
Materia:	Effective magnetic anisotropy ; Ferromagnetic and anti-ferromagnetic ; First-principles calculation ; Interfacial magnetic anisotropies ; Magnetic anisotropy energy ; Magnetic tunnel junction ; Spin reorientation transitions ; Tunneling magnetoresistance
Publicado en:	Physical review applied, Vol. 9, Issue 5 (May 2018) , art. 54048, ISSN 2331-7019

DOI: 10.1103/PhysRevApplied.9.054048

Postprint 7 p, 1.4 MB

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Documentos de investigación > Documentos de los grupos de investigación de la UAB > Centros y grupos de investigación (producción científica) > Ciencias > Institut Català de Nanociència i Nanotecnologia (ICN2)
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