Effect of interfacial structures on spin dependent tunneling in epitaxial L10-FePt/MgO/FePt perpendicular magnetic tunnel junctions

Yang, G.; Li, D. L.; Wang, S. G.; Ma, Q. L.; Liang, S. H.; Wei, H. X.; Han, X. F.; Hesjedal, T.; Ward, R. C.  C.; Kohn, A.; Elkayam, A.; Tal, N.; Zhang, X. -G.

doi:10.1063/1.4913265

Effect of interfacial structures on spin dependent tunneling in epitaxial L1₀-FePt/MgO/FePt perpendicular magnetic tunnel junctions

Journal Article · Tue Feb 24 00:00:00 EST 2015 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4913265· OSTI ID:1265531

Yang, G. ^[1]; Li, D. L. ^[1]; Wang, S. G. ^[1]; Ma, Q. L. ^[1]; Liang, S. H. ^[1]; Wei, H. X. ^[1]; Han, X. F. ^[1]; ^[2]; Ward, R. C. C. ^[2]; Kohn, A. ^[3]; Elkayam, A. ^[3]; Tal, N. ^[3]; Zhang, X. -G. ^[4]

Chinese Academy of Sciences (CAS), Beijing (China). State Key Lab. of Magnetism. Beijing National Lab. for Condensed Matter Physics. Inst. of Physics
Univ. of Oxford (United Kingdom). Clarendon Lab. Dept. of Physics
Ben-Gurion Univ. of the Negev, Beer-Sheva (Israel). Dept. of Materials Engineering. Ilse Katz Inst. for Nanoscale Science and Technology
Univ. of Florida, Gainesville, FL (United States). Dept. of Physics. Quantum Theory Project; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences. Computer Science and Mathematics Division

In this study, epitaxial FePt(001)/MgO/FePt magnetic tunnel junctions with L1₀-FePt electrodes showing perpendicular magnetic anisotropy were fabricated by molecular beam epitaxial growth. Tunnel magnetoresistance ratios of 21% and 53% were obtained at 300 K and 10 K, respectively. Our previous work, based on transmission electron microscopy, confirmed a semi-coherent interfacial structure with atomic steps (Kohn et al., APL 102, 062403 (2013)). Here, we show by x-ray photoemission spectroscopy and first-principles calculation that the bottom FePt/MgO interface is either Pt-terminated for regular growth or when an Fe layer is inserted at the interface, it is chemically bonded to O. Finally, both these structures have a dominant role in spin dependent tunneling across the MgO barrier resulting in a decrease of the tunneling magnetoresistance ratio compared with previous predictions.

View Accepted Manuscript (DOE)

Research Organization:: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Sponsoring Organization:: USDOE

Contributing Organization:: Ben-Gurion Univ. of the Negev, Beer-Sheva (Israel); Chinese Academy of Sciences (CAS), Beijing (China)

OSTI ID:: 1265531

Alternate ID(s):: OSTI ID: 22413156

Journal Information:: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 8 Vol. 117; ISSN 0021-8979

Publisher:: American Institute of Physics (AIP)Copyright Statement

Country of Publication:: United States

Language:: English

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Influence of HfO ₂ interlayers on magnetocrystalline anisotropy in Fe \|MgO \|Fe magnetic tunnel junction: First-principles investigation Chen, W. Z.; Zhang, J.; Yang, B. S. Journal of Applied Physics, Vol. 125, Issue 23 https://doi.org/10.1063/1.5095654	journal	June 2019
Tunnel magnetoresistance in ultrathin L1 ₀ MnGa/MgO perpendicular magnetic tunnel junctions Suzuki, K. Z.; Miura, Y.; Ranjbar, R. Journal of Physics D: Applied Physics, Vol. 51, Issue 23 https://doi.org/10.1088/1361-6463/aac00d	journal	May 2018
[Co/Ni] multilayers with robust post-annealing performance for spintronics device applications Gupta, S.; Sbiaa, R.; Al Bahri, M. Journal of Physics D: Applied Physics, Vol. 51, Issue 46 https://doi.org/10.1088/1361-6463/aae1ec	journal	October 2018

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36 MATERIALS SCIENCE
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