Minerals have the general trend of having a constant conductivity at high temperatures, but at low temperatures it decreases as temperature decreases. Porosity has a large effect on thermal conductivity. Air with a thermal conductivity of 0.025 W (m-K) at 300K (Grigull and Sandner, 1990),...
The thermal conductivity of polycrystalline ytterbium between 90K and 300K was found to increase with temperature. The additional contribution to the thermal conductivity is likely to be due to the bipolar term.doi:10.1016/0375-9601(73)90871-2D.G.S. Chuah...
A signature of electron-hole coupling in semiconductors is the bipolar thermal conduction at elevated temperatures, when the calculated lattice thermal conductivity (κ-LσΤ, where κ is the total thermal conductivity, L the Lorenz number, σ the electrical conductivity, and T the absolute ...
The development of cryogenic semiconductor electronics and superconducting quantum computing requires composite materials that can provide both thermal conduction and thermal insulation. We demonstrated that at cryogenic temperatures, the thermal conductivity of graphene composites can be both higher and lower t...
In this work the normalised wall heat flux is analysed and is defined as Φw=|qw|/[ρRSLcpR(Tad−TR)], where qw=−λw∂T^/∂y|w is the dimensional wall heat flux, λ is the thermal conductivity of the reacting gases and cpR is the specific heat capacity of the reactants....
5 at% Cu-Bi2Te3was prepared using flame-furnace-melting followed by quenching in these two mediums. This strategy aids in reducing thermal conductivity and improving mechanical hardness. SEM micrographs of both theBTC-Bq\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym}...
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These findings are interpreted on the basis of theories developed by Gruneisen and of Makinson.Robert W. PowersJohn B. ZieglerHerrick L. JohnstonPowells, R.W., Schawartz, D., and Johnston, H.L., The Thermal Conductivity of Metals and Alloys at Low Temperature. 1951, Ohio State University...
crystals Article Lattice Thermal Conductivity of mGeTe•nSb2Te3 Phase-Change Materials: A First-Principles Study Yuanchun Pan *, Zhen Li and Zhonglu Guo School of Materials Science and Engineering, Beihang University, Beijing 100191, China; zli@buaa.edu.cn (Z.L.); zlguo@buaa.edu.cn (Z....
However, the origin of this asymmetric dependence of thermal conductivity is different between bulks and nanomaterials. For the bulk device with two dissimilar materials connecting at an interface, it is necessary to have different temperature-dependent thermal conductivities in each segment to result in...