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Title: Magnetic bead detection using domain wall-based nanosensor

We investigate the effect of a single magnetic bead (MB) on the domain wall (DW) pinning/depinning fields of a DW trapped at the corner of an L-shaped magnetic nanodevice. DW propagation across the device is investigated using magnetoresistance measurements. DW pinning/depinning fields are characterized in as-prepared devices and after placement of a 1 μm-sized MB (Dynabeads{sup ®} MyOne{sup ™}) at the corner. The effect of the MB on the DW dynamics is seen as an increase in the depinning field for specific orientations of the device with respect to the external magnetic field. The shift of the depinning field, ΔB{sub dep} = 4.5–27.0 mT, is highly stable and reproducible, being significantly above the stochastic deviation which is about 0.5 mT. The shift in the deppinning field is inversely proportional to the device width and larger for small negative angles between the device and the external magnetic field. Thus, we demonstrate that DW-based devices can be successfully used for detection of single micron size MB.
Authors:
 [1] ;  [2] ; ;  [3] ;  [4] ;  [1] ;  [2] ;  [5] ;  [1]
  1. National Physical Laboratory, Teddington TW11 0LW (United Kingdom)
  2. (United Kingdom)
  3. Physikalisch-Technische Bundesanstalt, Braunschweig D-38116 (Germany)
  4. Istituto Nazionale di Ricerca Metrologica, Torino I-10135 (Italy)
  5. Royal Holloway University of London, Egham TW20 0EX (United Kingdom)
Publication Date:
OSTI Identifier:
22410149
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; DETECTION; DOMAIN STRUCTURE; MAGNETIC FIELDS; MAGNETIC MATERIALS; MAGNETORESISTANCE; NANOSTRUCTURES; ORIENTATION; SENSORS; STOCHASTIC PROCESSES; TRAPPING