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This content will become publicly available on October 28, 2016

Title: Acoustic phonon spectrum and thermal transport in nanoporous alumina arrays

We report results of a combined investigation of thermal conductivity and acoustic phonon spectra in nanoporous alumina membranes with the pore diameter decreasing from D=180 nm to 25 nm. The samples with the hexagonally arranged pores were selected to have the same porosity Ø ≈13%. The Brillouin-Mandelstam spectroscopy measurements revealed bulk-like phonon spectrum in the samples with D=180-nm pores and spectral features, which were attributed to spatial confinement, in the samples with 25-nm and 40-nm pores. The velocity of the longitudinal acoustic phonons was reduced in the samples with smaller pores. As a result, analysis of the experimental data and calculated phonon dispersion suggests that both phonon-boundary scattering and phonon spatial confinement affect heat conduction in membranes with the feature sizes D<40 nm.
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  1. Univ. of California, Riverside, CA (United States)
Publication Date:
OSTI Identifier:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Applied Physics Letters
Additional Journal Information:
Journal Volume: 107; Journal Issue: 18; Conference: Brillouin-Mandelstam Light Scattering Spectroscopy of the Nanoscale Phononic Superlattice Arrays, Nonlinear Optics 2015, , Kauai, HI (United States), 26–31 Jul 2015
Research Org:
Univ. of California, Riverside, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
thermal conductivity; Brillouin-Mandelstam light scattering; phonon confinement; nanoporous alumina; acoustic scattering; nanoporous materials; heat conduction