Thin-film boundary conditions

1992 ◽  
Vol 5 (13) ◽  
pp. 682-685 ◽  
Author(s):  
Shyh-Kang Jeng ◽  
Shung-Wu Lee
Physica ◽  
1963 ◽  
Vol 29 (11) ◽  
pp. 1219-1230 ◽  
Author(s):  
C.W. Searle ◽  
A.H. Morrish ◽  
R.J. Prosen

Author(s):  
Zhengxing Huang ◽  
Zhenan Tang ◽  
Suyuan Bai ◽  
Jun Yu

For crystal materials, thermal conductivity (TC) is proportional to T3 at low temperatures and to T−1 at high temperatures. TCs of most amorphous materials decrease with the decreasing temperatures. If a material is thin film, boundary will influence the TC and then influence the temperature dependence. In this paper, we calculate the TC of crystal and amorphous SiO2 thin films, which is a commonly used material in micro devices and Integrated Circuits, by NEMD simulations. The calculation temperatures are from 100K to 700K and the thicknesses are from 2nm to 8nm. TCs of crystal thin films reach their peak values at different temperatures for different thicknesses. The smaller thickness the larger peak values obtained. But for amorphous thin films, the results show that the temperature dependence of thin films is the same as bulk materials and not relative to their thicknesses. The obtained temperature dependence of the thin films is consistent with some previous measurements and the theory predictions.


1976 ◽  
Vol 190 (1) ◽  
pp. 627-633 ◽  
Author(s):  
H. McCallion ◽  
D. R. Wales

SYNOPSIS A computer program representing a shaft and rotor whirling in bearings which allows for realistic oil film boundary conditions and non-circular bearing profiles has been developed. It gave good agreement with experimental results published by Brown and France. With the aim of increasing understanding of the influence of bearing profile on system instability, the program calculates the timewise variation of the energy in translational motion supplied to the rotor by oil film forces. One case is illustrated.


Author(s):  
Carlos J. Gomes ◽  
Marcela Madrid ◽  
Cristina H. Amon

The in-plane thermal conductivity of thin silicon films is predicted using equilibrium molecular dynamics, the Stillinger-Weber potential and the Green-Kubo relationship. Film thicknesses range from 2 to 200 nm. Periodic boundary conditions are used in the directions parallel to the thin film surfaces. Two different strategies are evaluated to treat the atoms on the surfaces perpendicular to the thin film direction: adding four layers of atoms kept frozen at their crystallographic positions, or restraining the atoms near the surfaces with a repulsive potential. We show that when the thin-film thickness is smaller than the phonon mean free path, the predictions of the in-plane thermal conductivity at 1000K differ significantly depending on the potential applied to the atoms near the surfaces. In this limit, the experimentally observed trend of decreasing thermal conductivity with decreasing film thickness is predicted when the surface atoms are subject to a repulsive potential in addition to the Stillinger-Weber potential, but not when they are limited by frozen atoms.


1984 ◽  
Vol 29 (2) ◽  
pp. 976-982 ◽  
Author(s):  
V. M. Agranovich ◽  
V. E. Kravtsov ◽  
T. A. Leskova ◽  
A. G. Mal'shukov ◽  
G. Hernández-Cocoletz ◽  
...  

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