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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

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
Resource Relation:
Journal Name: AIP Advances; Journal Volume: 5; Journal Issue: 4; Other Information: (c) 2015 Author(s); Country of input: International Atomic Energy Agency (IAEA)
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