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Title: Suppression of stochastic pinning in magnetic nanowire devices using “virtual” domain walls

We have investigated the pinning and depinning of “virtual” domain walls in planar magnetic nanowires. Such virtual walls are created when a conventional domain wall becomes annihilated at a narrow gap between two segments of a discontinuous nanowire. By using focused magneto-optical Kerr effect magnetometry to study the repeatability of their depinning, we show that virtual walls exhibit single-mode depinning distributions, characterized by remarkably low, sub-Oersted standard deviations. This is in stark contrast to the depinning of domain walls from conventional notch-shaped defects, which typically exhibit multi-mode depinning field distributions spanning tens to hundreds of Oersteds. High-resolution magnetic soft x-ray microscopy measurements are used to reveal that this high level of repeatability is the result of a simple mediated-nucleation process, which decouples the depinning mechanism from structure of the initially injected DWs. Our work serves as an example of how the complex and dynamical stochastic behaviors exhibited by domain walls in nanowires can be controlled.
Authors:
;  [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [4] ;  [6]
  1. Department of Materials Science and Engineering, University of Sheffield, Sheffield (United Kingdom)
  2. Department of Cardiovascular Science, University of Sheffield, Sheffield (United Kingdom)
  3. Nanoscience and Technology Centre, University of Sheffield, Sheffield (United Kingdom)
  4. Center for X-ray Optics, Lawrence Berkeley National Lab, Berkeley, California 94720 (United States)
  5. (Korea, Republic of)
  6. (United States)
Publication Date:
OSTI Identifier:
22305714
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 12; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; 77 NANOSCIENCE AND NANOTECHNOLOGY; DEFECTS; DISTRIBUTION; EQUIPMENT; INHIBITION; KERR EFFECT; MAGNETIC MATERIALS; MICROSCOPY; NANOWIRES; QUANTUM WIRES; RESOLUTION; SOFT X RADIATION; STOCHASTIC PROCESSES