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Title: Joint perpendicular anisotropy and strong interlayer exchange coupling in systems with thin vanadium spacers

We study the influence of the insertion of a vanadium spacer layer between an FeCoB layer and a [Co/Ni] multilayer in an MgO substrate-based system mimicking the reference system of a perpendicular anisotropy magnetic tunnel junction. The anisotropy of the [Co/Ni] multilayer gradually improves with the vanadium thicknesses t, up to an optimized state for t = 8 Å, with little influence of the thermal annealing. The interlayer exchange coupling is ferromagnetic and very strong for t≤6 Å. It can be adjusted by thermal treatment at t = 8 Å from no coupling in the as-grown state to more than 2 mJ/m{sup 2} after 250 °C annealing. For this spacer thickness, the magnetic properties are consistent with the occurrence of a bcc (001) to an fcc (111) crystalline structure transition at the vanadium spacer. The remaining interlayer exchange coupling at t = 8 Å is still substantially higher than the one formerly obtained with a Tantalum spacer, which holds promise for further optimization of the reference layers of tunnel junctions meant for magnetic random access memories.
Authors:
; ; ;  [1] ;  [2]
  1. Institut d'Electronique Fondamentale, CNRS, UMR 8622, Orsay (France)
  2. (France)
Publication Date:
OSTI Identifier:
22402916
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 16; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ANISOTROPY; ANNEALING; BCC LATTICES; COBALT; COBALT BORIDES; COUPLING; FCC LATTICES; HETEROJUNCTIONS; IRON COMPOUNDS; LAYERS; MAGNESIUM OXIDES; MAGNETIC PROPERTIES; NICKEL; RANDOMNESS; SPACERS; SUBSTRATES; TANTALUM; TEMPERATURE DEPENDENCE; TUNNEL EFFECT; VANADIUM