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Title: Hanle measurements of electrodeposited Fe/GaAs spin tunnel contacts

We report spin transport in electrodeposited Fe/n-GaAs tunnel diodes via three-terminal Hanle measurements. For temperatures between 20 K and 150 K, the spin resistance was up to 20 times higher than expected from theoretical calculations and 1000 times larger compared to a vacuum-deposited counterpart. This higher spin resistance was correlated with a higher contact resistance, and a higher concentration of oxygen impurities in the electrodeposited Fe film and interface, as detected via x-ray photoelectron and Auger spectroscopies, and inferred from Fe film nucleation rates. These results can be explained via a small effective tunnel-contact area of 5%, but extra spin filtering via interfacial states or magnetic oxide layers cannot be ruled out. The spin diffusion times (8.5 ± 0.4 ns to 1.8 ± 0.4 ns, for 20 K to 150 K) extracted from Lorentzian fits were in good agreement with values obtained from earlier 4-terminal Hanle measurements (7.8 ± 0.4 ns to 3.2 ± 0.4 ns, for 25 K to 77 K), both 10 times slower than reported vacuum-deposited contacts.
Authors:
; ; ;  [1] ;  [2]
  1. Department of Physics, Simon Fraser University, Burnaby, British Columbia V5A 1S6 (Canada)
  2. National Research Council, 1200 Montreal Rd, Ottawa, Ontario K1A 0R6 (Canada)
Publication Date:
OSTI Identifier:
22271122
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; 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:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; AUGER ELECTRON SPECTROSCOPY; COMPARATIVE EVALUATIONS; CONCENTRATION RATIO; DIFFUSION; ELECTRODEPOSITION; GALLIUM ARSENIDES; INTERFACES; IRON; LAYERS; NUCLEATION; OXIDES; OXYGEN; SPIN; TEMPERATURE DEPENDENCE; THIN FILMS; TUNNEL DIODES; X-RAY SPECTROSCOPY