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Title: Interface composition between Fe{sub 3}O{sub 4} nanoparticles and GaAs for spintronic applications

Recent interest in spintronic applications has necessitated the study of magnetic materials in contact with semiconductor substrates; importantly, the structure and composition of these interfaces can influence both device functionality and the magnetic properties. Nanoscale ferromagnet/semiconductor structures are of particular interest. In this study, the interface structure between a monolayer of ferromagnetic magnetite (Fe{sub 3}O{sub 4}) nanoparticles and a GaAs substrate was studied using cross-sectional transmission electron microscopy techniques. It was found that a continuous amorphous oxide interface layer separates the nanoparticles from the GaAs substrate, and that iron diffused into the interface layer forming a compositional gradient. Electron energy-loss near-edge fine structures of the O K absorption edge revealed that the amorphous oxide is composed of γ-Fe{sub 2}O{sub 3} directly underneath the Fe{sub 3}O{sub 4} nanoparticles, followed by a solid solution of Ga{sub 2}O{sub 3} and FeO and mostly Ga{sub 2}O{sub 3} when approaching the buckled oxide/substrate interface. Real-space density functional theory calculations of the dynamical form factor confirmed the experimental observations. The implication of the findings on the optimization of these structures for spin injection is discussed.
Authors:
 [1] ;  [2] ;  [3] ;  [1]
  1. Department of Chemical Engineering and Materials Science, University of California, Davis, California 95695 (United States)
  2. (United States)
  3. Department of Electrical and Computer Engineering, University of California, Davis, California 95695 (United States)
Publication Date:
OSTI Identifier:
22314353
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 8; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ENERGY LOSSES; FERRITES; FINE STRUCTURE; FORM FACTORS; GALLIUM ARSENIDES; GALLIUM OXIDES; INTERFACES; IRON; IRON OXIDES; K ABSORPTION; LAYERS; MAGNETIC PROPERTIES; NANOPARTICLES; NANOSTRUCTURES; SOLID SOLUTIONS; SPIN; SUBSTRATES; TRANSMISSION ELECTRON MICROSCOPY