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Title: Thermal flux limited electron Kapitza conductance in copper-niobium multilayers

We study the interplay between the contributions of electron thermal flux and interface scattering to the Kapitza conductance across metal-metal interfaces through measurements of thermal conductivity of copper-niobium multilayers. Thermal conductivities of copper-niobium multilayer films of period thicknesses ranging from 5.4 to 96.2 nm and sample thicknesses ranging from 962 to 2677 nm are measured by time-domain thermoreflectance over a range of temperatures from 78 to 500 K. The Kapitza conductances between the Cu and Nb interfaces in multilayer films are determined from the thermal conductivities using a series resistor model and are in good agreement with the electron diffuse mismatch model. Our results for the thermal boundary conductance between Cu and Nb are compared to literature values for the thermal boundary conductance across Al-Cu and Pd-Ir interfaces, and demonstrate that the interface conductance in metallic systems is dictated by the temperature derivative of the electron energy flux in the metallic layers, rather than electron mean free path or scattering processes at the interface.
Authors:
; ; ;  [1] ; ; ; ;  [2] ;  [3] ;  [4] ;  [5]
  1. Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia 22904 (United States)
  2. Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States)
  3. Department of Materials Science and Engineering, University of California, Berkeley, California 94720 (United States)
  4. Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
  5. Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)
Publication Date:
OSTI Identifier:
22412772
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 106; Journal Issue: 9; Other Information: (c) 2015 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; ALUMINIUM; COMPARATIVE EVALUATIONS; COPPER; ELECTRONS; FILMS; INTERFACES; IRIDIUM; LAYERS; MEAN FREE PATH; NIOBIUM; PALLADIUM; RESISTORS; THERMAL CONDUCTIVITY