First-principles calculations of phonon transport across a vacuum gap

Phonon transport across a vacuum gap

D. P. Sellan,1 E. S. Landry,2,3 K. Sasihithlu,4 A. Narayanaswamy,4 A. J. H. McGaughey,3,* and C. H. Amon1,3 1Department of Mechanical & Industrial Engineering, University of Toronto, Toronto, Ontario M5S 3G8, Canada 2United Technologies Research Center, East Hartford, Connecticut 06108, USA 3Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA 4D...

Phonon thermal transport in Bi2Te3 from first principles

Phonon anharmonicity of rutile SnO2 studied by Raman spectrometry and first principles calculations of the kinematics of phonon-phonon interactions

Raman spectra of rutile tin dioxide (SnO2) were measured at temperatures from 83 to 873 K. The pure anharmonicity from phonon-phonon interactions was found to be large and comparable to the quasiharmonicity. First-principles calculations of phonon dispersions were used to assess the kinematics of three-phonon and four-phonon processes. These kinematics were used to generate Raman peak widths an...

Mechanics of defect transport in tungsten from first-principles calculations

p, li {white-space: prewrap;} Tungsten (W) is an important material for high temperature applications due to its refractory nature. However, like all transition metals from the VI-A group, W suffers from low-temperature brittleness and lack of ductility, which severely limits its use as a structural material. Tungsten’s mechanical properties can be enhanced by alloying with elements with d-elec...

Heat transport in silicon from first-principles calculations

Using harmonic and anharmonic force constants extracted from density functional calculations within a supercell, we have developed a relatively simple but general method to compute thermodynamic and thermal properties of any crystal. First, from the harmonic, cubic, and quartic force constants, we construct a force field for molecular dynamics. It is exact in the limit of small atomic displacem...