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Title: Sign change in the tunnel magnetoresistance of Fe{sub 3}O{sub 4}/MgO/Co-Fe-B magnetic tunnel junctions depending on the annealing temperature and the interface treatment

Abstract

Magnetite (Fe{sub 3}O{sub 4}) is an eligible candidate for magnetic tunnel junctions (MTJs) since it shows a high spin polarization at the Fermi level as well as a high Curie temperature of 585°C. In this study, Fe{sub 3}O{sub 4}/MgO/Co-Fe-B MTJs were manufactured. A sign change in the TMR is observed after annealing the MTJs at temperatures between 200°C and 280°C. Our findings suggest an Mg interdiffusion from the MgO barrier into the Fe{sub 3}O{sub 4} as the reason for the change of the TMR. Additionally, different treatments of the magnetite interface (argon bombardment, annealing at 200°C in oxygen atmosphere) during the preparation of the MTJs have been studied regarding their effect on the performance of the MTJs. A maximum TMR of up to -12% could be observed using both argon bombardment and annealing in oxygen atmosphere, despite exposing the magnetite surface to atmospheric conditions before the deposition of the MgO barrier.

Authors:
; ; ; ; ; ; ;  [1]; ; ; ; ; ;  [2]
  1. Center for Spinelectronic Materials and Devices, Physics Department, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld (Germany)
  2. Fachbereich Physik, Universität Osnabrück, Barbarastraße 7, 49069 Osnabrück (Germany)
Publication Date:
OSTI Identifier:
22488525
Resource Type:
Journal Article
Journal Name:
AIP Advances
Additional Journal Information:
Journal Volume: 5; Journal Issue: 4; Other Information: (c) 2015 Author(s); Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 2158-3226
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ANNEALING; ARGON; CURIE POINT; DEPOSITION; FERMI LEVEL; FERRITES; INTERFACES; IRON OXIDES; MAGNESIUM OXIDES; MAGNETITE; MAGNETORESISTANCE; OXYGEN; SPIN ORIENTATION; SUPERCONDUCTING JUNCTIONS; SURFACES; TUNNEL EFFECT; TUNNEL JUNCTIONS

Citation Formats

Marnitz, L., E-mail: lmarnitz@physik.uni-bielefeld.de, Rott, K., Niehörster, S., Klewe, C., Meier, D., Fabretti, S., Thomas, A., Reiss, G., Kuschel, T., Witziok, M., Krampf, A., Kuschel, O., Schemme, T., Kuepper, K., and Wollschläger, J. Sign change in the tunnel magnetoresistance of Fe{sub 3}O{sub 4}/MgO/Co-Fe-B magnetic tunnel junctions depending on the annealing temperature and the interface treatment. United States: N. p., 2015. Web. doi:10.1063/1.4917018.
Marnitz, L., E-mail: lmarnitz@physik.uni-bielefeld.de, Rott, K., Niehörster, S., Klewe, C., Meier, D., Fabretti, S., Thomas, A., Reiss, G., Kuschel, T., Witziok, M., Krampf, A., Kuschel, O., Schemme, T., Kuepper, K., & Wollschläger, J. Sign change in the tunnel magnetoresistance of Fe{sub 3}O{sub 4}/MgO/Co-Fe-B magnetic tunnel junctions depending on the annealing temperature and the interface treatment. United States. https://doi.org/10.1063/1.4917018
Marnitz, L., E-mail: lmarnitz@physik.uni-bielefeld.de, Rott, K., Niehörster, S., Klewe, C., Meier, D., Fabretti, S., Thomas, A., Reiss, G., Kuschel, T., Witziok, M., Krampf, A., Kuschel, O., Schemme, T., Kuepper, K., and Wollschläger, J. 2015. "Sign change in the tunnel magnetoresistance of Fe{sub 3}O{sub 4}/MgO/Co-Fe-B magnetic tunnel junctions depending on the annealing temperature and the interface treatment". United States. https://doi.org/10.1063/1.4917018.
@article{osti_22488525,
title = {Sign change in the tunnel magnetoresistance of Fe{sub 3}O{sub 4}/MgO/Co-Fe-B magnetic tunnel junctions depending on the annealing temperature and the interface treatment},
author = {Marnitz, L., E-mail: lmarnitz@physik.uni-bielefeld.de and Rott, K. and Niehörster, S. and Klewe, C. and Meier, D. and Fabretti, S. and Thomas, A. and Reiss, G. and Kuschel, T. and Witziok, M. and Krampf, A. and Kuschel, O. and Schemme, T. and Kuepper, K. and Wollschläger, J.},
abstractNote = {Magnetite (Fe{sub 3}O{sub 4}) is an eligible candidate for magnetic tunnel junctions (MTJs) since it shows a high spin polarization at the Fermi level as well as a high Curie temperature of 585°C. In this study, Fe{sub 3}O{sub 4}/MgO/Co-Fe-B MTJs were manufactured. A sign change in the TMR is observed after annealing the MTJs at temperatures between 200°C and 280°C. Our findings suggest an Mg interdiffusion from the MgO barrier into the Fe{sub 3}O{sub 4} as the reason for the change of the TMR. Additionally, different treatments of the magnetite interface (argon bombardment, annealing at 200°C in oxygen atmosphere) during the preparation of the MTJs have been studied regarding their effect on the performance of the MTJs. A maximum TMR of up to -12% could be observed using both argon bombardment and annealing in oxygen atmosphere, despite exposing the magnetite surface to atmospheric conditions before the deposition of the MgO barrier.},
doi = {10.1063/1.4917018},
url = {https://www.osti.gov/biblio/22488525}, journal = {AIP Advances},
issn = {2158-3226},
number = 4,
volume = 5,
place = {United States},
year = {Wed Apr 15 00:00:00 EDT 2015},
month = {Wed Apr 15 00:00:00 EDT 2015}
}