skip to main content

SciTech ConnectSciTech Connect

Title: Seeking to quantify the ferromagnetic-to-antiferromagnetic interface coupling resulting in exchange bias with various thin-film conformations

Ni{sub 3}Fe/(Ni, Fe)O thin films with bilayer and nanocrystallite dispersion morphologies are prepared with a dual ion beam deposition technique permitting precise control of nanocrystallite growth, composition, and admixtures. A bilayer morphology provides a Ni{sub 3}Fe-to-NiO interface, while the dispersion films have different mixtures of Ni{sub 3}Fe, NiO, and FeO nanocrystallites. Using detailed analyses of high resolution transmission electron microscopy images with Multislice simulations, the nanocrystallites' structures and phases are determined, and the intermixing between the Ni{sub 3}Fe, NiO, and FeO interfaces is quantified. From field-cooled hysteresis loops, the exchange bias loop shift from spin interactions at the interfaces are determined. With similar interfacial molar ratios of FM-to-AF, we find the exchange bias field essentially unchanged. However, when the interfacial ratio of FM to AF was FM rich, the exchange bias field increases. Since the FM/AF interface ‘contact’ areas in the nanocrystallite dispersion films are larger than that of the bilayer film, and the nanocrystallite dispersions exhibit larger FM-to-AF interfacial contributions to the magnetism, we attribute the changes in the exchange bias to be from increases in the interfacial segments that suffer defects (such as vacancies and bond distortions), that also affects the coercive fields.
Authors:
; ;  [1] ; ;  [2] ;  [3]
  1. Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 300, Taiwan (China)
  2. Department of Physics and Astronomy, University of Manitoba, Winnipeg, MB R3T 2N2 (Canada)
  3. Department of Materials Science and Engineering, National Chung Hsing University, Taichung 402, Taiwan (China)
Publication Date:
OSTI Identifier:
22314557
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 5; Other Information: (c) 2014 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; ANTIFERROMAGNETISM; CRYSTAL GROWTH; DEPOSITION; HYSTERESIS; INTERFACES; IRON OXIDES; LAYERS; MIXTURES; MORPHOLOGY; NICKEL OXIDES; SIMULATION; THIN FILMS; TRANSMISSION ELECTRON MICROSCOPY; VACANCIES