Site-Resolved Contributions to the Magnetic-Anisotropy Energy and Complex Spin Structure of Fe/MgO Sandwiches

Ramón Cuadrado, László Oroszlány, András Deák, Thomas A. Ostler, Andrea Meo, Roman V. Chepulskii, Dmytro Apalkov, Richard F.L. Evans, L. Szunyogh, Roy W. Chantrell

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

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.

Original languageEnglish
Article number054048
JournalPhysical Review Applied
Volume9
Issue number5
DOIs
Publication statusPublished - May 30 2018

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anisotropy
tunnel junctions
magnetic properties
magnetization
temperature dependence
temperature
energy
retraining
Curie temperature
thermal stability
energy transfer
interactions
optimization
ground state
electronics
ions
simulation

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Cuadrado, R., Oroszlány, L., Deák, A., Ostler, T. A., Meo, A., Chepulskii, R. V., ... Chantrell, R. W. (2018). Site-Resolved Contributions to the Magnetic-Anisotropy Energy and Complex Spin Structure of Fe/MgO Sandwiches. Physical Review Applied, 9(5), [054048]. https://doi.org/10.1103/PhysRevApplied.9.054048

Site-Resolved Contributions to the Magnetic-Anisotropy Energy and Complex Spin Structure of Fe/MgO Sandwiches. / Cuadrado, Ramón; Oroszlány, László; Deák, András; Ostler, Thomas A.; Meo, Andrea; Chepulskii, Roman V.; Apalkov, Dmytro; Evans, Richard F.L.; Szunyogh, L.; Chantrell, Roy W.

In: Physical Review Applied, Vol. 9, No. 5, 054048, 30.05.2018.

Research output: Contribution to journalArticle

Cuadrado, R, Oroszlány, L, Deák, A, Ostler, TA, Meo, A, Chepulskii, RV, Apalkov, D, Evans, RFL, Szunyogh, L & Chantrell, RW 2018, 'Site-Resolved Contributions to the Magnetic-Anisotropy Energy and Complex Spin Structure of Fe/MgO Sandwiches', Physical Review Applied, vol. 9, no. 5, 054048. https://doi.org/10.1103/PhysRevApplied.9.054048
Cuadrado, Ramón ; Oroszlány, László ; Deák, András ; Ostler, Thomas A. ; Meo, Andrea ; Chepulskii, Roman V. ; Apalkov, Dmytro ; Evans, Richard F.L. ; Szunyogh, L. ; Chantrell, Roy W. / Site-Resolved Contributions to the Magnetic-Anisotropy Energy and Complex Spin Structure of Fe/MgO Sandwiches. In: Physical Review Applied. 2018 ; Vol. 9, No. 5.
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