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Title: Effects of repetitive bending on the magnetoresistance of a flexible spin-valve

A positive magnetostrictive single layer (CoFe) and top-pinned spin-valve structure with positive magnetostrictive free (NiFe) and pinned (CoFe) layers were deposited on flexible polyethylene terephthalate film to investigate the changes in the magnetic properties in flexible environments, especially with a repetitive bending process. It was found that the stress, applied by repetitive bending, changes significantly the magnetic anisotropy of both layers in a single and spin-valve structure depending on the direction of applied stress. The changes in magnetic anisotropy were understood in terms of the inverse magnetostriction effect (the Villari effect) and the elastic recovery force from the flexibility of the polymer substrate. Repetitive bending with tensile stress transverse (or parallel) to the magnetic easy axis was found to enhance (or reduce) the magnetic anisotropy and, consequently, the magnetoresistance ratio of a spin-valve. The observed effects of bending stress in this study should be considered for the practical applications of electro-magnetic devices, especially magneto-striction sensor.
Authors:
; ;  [1] ;  [2] ;  [3]
  1. School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of)
  2. Department of Physics, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)
  3. Department of Physics, Sejong University, Seoul 143-747 (Korea, Republic of)
Publication Date:
OSTI Identifier:
22410135
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 17; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANISOTROPY; COBALT; FILMS; FLEXIBILITY; INTERMETALLIC COMPOUNDS; IRON; LAYERS; MAGNETORESISTANCE; MAGNETOSTRICTION; NICKEL; POLYESTERS; SENSORS; SPIN; STRESSES; SUBSTRATES; VALVES