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Title: Moderate positive spin Hall angle in uranium

We report measurements of spin pumping and the inverse spin Hall effect in Ni{sub 80}Fe{sub 20}/uranium bilayers designed to study the efficiency of spin-charge interconversion in a super-heavy element. We employ broad-band ferromagnetic resonance on extended films to inject a spin current from the Ni{sub 80}Fe{sub 20} (permalloy) into the uranium layer, which is then converted into an electric field by the inverse spin Hall effect. Surprisingly, our results suggest a spin mixing conductance of order 2 × 10{sup 19} m{sup −2} and a positive spin Hall angle of 0.004, which are both merely comparable with those of several transition metals. These results thus support the idea that the electronic configuration may be at least as important as the atomic number in governing spin pumping across interfaces and subsequent spin Hall effects. In fact, given that both the magnitude and the sign are unexpected based on trends in d-electron systems, materials with unfilled f-electron orbitals may hold additional exploration avenues for spin physics.
Authors:
; ;  [1] ;  [2] ;  [3]
  1. Department of Physics, University of Central Florida, Orlando, Florida 32816 (United States)
  2. H. H. Will Laboratory, University of Bristol, Bristol BS2 8BS (United Kingdom)
  3. School of Chemistry and Materials Science, Rochester Institute of Technology, Rochester, New York 14623 (United States)
Publication Date:
OSTI Identifier:
22486193
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 107; Journal Issue: 23; 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; COMPARATIVE EVALUATIONS; EFFICIENCY; ELECTRONIC STRUCTURE; FERROMAGNETIC RESONANCE; HALL EFFECT; LAYERS; PERMALLOY; SPIN; TRANSITION ELEMENTS; URANIUM