Acoustic phonon spectrum and thermal transport in nanoporous alumina arrays
- Univ. of California, Riverside, CA (United States)
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.
- Research Organization:
- Univ. of California, Riverside, CA (United States); Energy Frontier Research Centers (EFRC) (United States). Spins and Heat in Nanoscale Electronic Systems (SHINES)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- SC0012670
- OSTI ID:
- 1223601
- Journal Information:
- Applied Physics Letters, Vol. 107, 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; ISSN 0003-6951
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
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