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Title: Magnetic characteristics of a high-layer-number NiFe/FeMn multilayer

We report the static and dynamic magnetic characteristics of a high-layer-number NiFe/FeMn multilayer test structure with potential applications in broadband absorber and filter devices. To allow fine control over the absorption linewidths and to understand the mechanisms governing the resonances in a tailored structure similar to that expected to be used in real world applications, the multilayer was intentionally designed to have layer thickness and interface roughness variations. Magnetometry measurements show that the sample has complex hysteresis loops with features consistent with single ferromagnetic film reversals. Characterisation by transmission electron microscopy allows us to correlate the magnetic properties with structural features, including the film widths and interface roughnesses. Analysis of resonance frequencies from broadband ferromagnetic resonance measurements as a function of field magnitude and orientation provide values of the local exchange bias, rotatable anisotropy, and uniaxial anisotropy fields for specific layers in the stack and explain the observed mode softening. The linewidths of the multilayer are adjustable around the bias field, approaching twice that seen at larger fields, allowing control over the bandwidth of devices formed from the structure.
Authors:
; ; ;  [1] ; ;  [2]
  1. SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom)
  2. ANSIN, Department of Physics and Astronomy, Queen's University Belfast, Belfast BT7 1NN (United Kingdom)
Publication Date:
OSTI Identifier:
22492962
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 118; Journal Issue: 20; 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; FERROMAGNETIC RESONANCE; HYSTERESIS; INTERFACES; IRON COMPOUNDS; LAYERS; LINE WIDTHS; MAGNETIC PROPERTIES; NICKEL COMPOUNDS; ORIENTATION; ROUGHNESS; THICKNESS; THIN FILMS; TRANSMISSION ELECTRON MICROSCOPY