Universal temperature dependence of the thermal conductivity of clathrate compounds, molecular crystals, and glasses at low temperatures

2020 ◽  
Vol 46 (2) ◽  
pp. 111-117
Author(s):  
O. A. Korolyuk ◽  
A. I. Krivchikov ◽  
O. O. Romantsova
Keyword(s):  
Thermal Conductivity ◽  
Temperature Dependence ◽  
Low Temperatures ◽  
Molecular Crystals ◽  
Clathrate Compounds

Variation in the Einstein Temperature of Guest Atoms in Ba-Ge-X type-III Clathrate Compounds

2007 ◽  
Vol 1044 ◽  
Author(s):  
Katsushi Tanaka ◽  
Jung-Hwan Kim ◽  
Kyosuke Kishida ◽  
Haruyuki Inui
Keyword(s):  
Thermal Conductivity ◽  
Temperature Dependence ◽  
Lattice Thermal Conductivity ◽  
Atomic Displacement ◽  
X Ray ◽  
Type Iii ◽  
Clathrate Compounds ◽  
Einstein Temperature ◽  
Small Lattice ◽  
Atomic Displacement Parameters

AbstractEinstein temperatures of guest atoms in Ba-Ge-(Al, In) type-III clathrate compounds have been estimated from the temperature dependence of the atomic displacement parameters determined by synchrotron X-ray powder diffractions. The lowest temperature is obtained for the vibration of Ba(2) atoms along the x-direction, which corresponds to the “rattling motion” of the guest atoms in the compounds. The temperature estimated is significantly low of about 50 K, which agrees with the fact that the compounds have small lattice thermal conductivities of about 0.6 W/mK. Though the lattice thermal conductivity of Ba24Ge88Al12 is larger than that of Ba24Ge88In12, the Einstein temperature of Ba24Ge88Al12 is slightly smaller than that of Ba24Ge88In12. This discrepancy can be explained by the consideration of higher Debye temperature of Ba24Ge88Al12 than that of Ba24Ge88In12, that is, lattice thermal conductivity without “rattling motion” is larger for Ba24Ge88Al12 than that for Ba24Ge88In12.

THEORY OF THERMAL CONDUCTIVITY IN MOLECULAR CRYSTALS, APPLICATION TO ALCALI CYANIDES

1981 ◽  
Vol 42 (C6) ◽  
pp. C6-247-C6-249 ◽  
Author(s):  
W. Bauernfeind ◽  
J. Keller ◽  
U. Schröder
Keyword(s):  
Thermal Conductivity ◽  
Molecular Crystals

TEMPERATURE DEPENDENCE BEHAVIOR OF ELECTRICAL RESISTIVITY IN NOBLE METALS AT LOW TEMPERATURES

2014 ◽  
Vol 5 (3) ◽  
pp. 982-992 ◽  
Author(s):  
M AL-Jalali
Keyword(s):  
Experimental Data ◽  
Electrical Resistivity ◽  
Temperature Dependence ◽  
Concentration Dependence ◽  
Low Temperatures ◽  
Noble Metals ◽  
Phonon Scattering ◽  
Theoretical Models ◽  
Residual Resistivity ◽  
Electron Phonon Scattering

Resistivity temperature – dependence and residual resistivity concentration-dependence in pure noble metals(Cu, Ag, Au) have been studied at low temperatures. Dominations of electron – dislocation and impurity, electron-electron, and electron-phonon scattering were analyzed, contribution of these mechanisms to resistivity were discussed, taking into consideration existing theoretical models and available experimental data, where some new results and ideas were investigated.

The Evaluation of TiTe2 as a Diffusion Barrier in the Formation of Low Thermal Conductivity Nanolaminates with Bi2Te3 and Sb2Te3

2010 ◽  
Vol 74 ◽  
pp. 38-47
Author(s):  
Clay Mortensen ◽  
Paul Zschack ◽  
David C. Johnson
Keyword(s):  
Thermal Conductivity ◽  
Diffusion Barrier ◽  
Self Assembly ◽  
Low Temperatures ◽  
Annealing Temperature ◽  
The Self ◽  
High Angle ◽  
X Ray Diffraction ◽  
Amorphous Precursor ◽  
X Ray

The evolution of designed [(Ti-Te)]x[(Sb-Te)]y, [(Bi-Te)]x[(Sb-Te)]y, [(Ti-Te)]w[(Bi-Te)]x[(Sb-Te)]y and [(Ti-Te)]w[(Bi-Te)]x[(Ti-Te)]y[(Sb-Te)]z precursors were followed as a function of annealing temperature and time using both low and high angle x-ray diffraction techniques to probe the self assembly into nanolaminate materials. The [(Bi-Te)]x[(Sb-Te)]y precursors were found to interdiffuse at low temperatures to form a (BixSb1-x)2Te3 alloy. The [(Ti-Te)]x[(Bi-Te)]y and [(Ti-Te)]x[(Sb-Te)]y precursors formed ordered nanolaminates [{(TiTe2)}1.35]x[Bi2Te3]y and [{(TiTe2)}1.35]x[Sb2Te3]y respectively. The [(Ti-Te)]w[(Bi-Te)]x[(Sb-Te)]x precursors formed [{(TiTe2)}1.35]w[(Bi0.5Sb0.5)2Te3]2x nanolaminates on annealing, as the bismuth and antimony layers interdiffused. Over the range of TiTe2 thicknesses used in [(Ti-Te)]w[(Bi-Te)]x[(Ti-Te)]y[(Sb-Te)]z precursors, Bi and Sb were found to interdiffuse through the 2-4 nm thick Ti-Te layers, resulting in the formation of (BixSb1-x)2Te3 alloy layers as part of the final nanolaminated products. When the Bi-Te and Sb-Te thicknesses were equal in the amorphous precursors, symmetric [{(TiTe2)}1.35]m[(Bi0.5Sb0.5)2Te3]n nanolamiantes were formed. When the thicknesses of Bi-Te and Sb-Te layers were not equal in the amorphous precursor, asymmetric [(TiTe2)1.35]m[(BixSb1-x)2Te3]n[(TiTe2)1.35]m[(BixSb1-x)2Te3]p nanolaminates were formed. These results imply that to form (A)w(B)x(C)y nanolaminates using designed layered precursors all three components must be immiscible. To form (A)x(B)y(A)x(C)z nanolaminates, the components must be immiscible or the precursor to the A component and the A component itself must be an effective interdiffusion barrier preventing B and C from mixing.

Thermal Property Measurements on Biological Materials at Subzero Temperatures

1991 ◽  
Vol 113 (4) ◽  
pp. 423-429 ◽  
Author(s):  
Xuemei Bai ◽  
David E. Pegg
Keyword(s):  
Thermal Conductivity ◽  
Low Temperatures ◽  
The Self ◽  
Rabbit Kidney ◽  
Kidney Cortex ◽  
Low Viscosity ◽  
Subzero Temperatures ◽  
Liquid Samples ◽  
Thermal Probes ◽  
Low Ionic Strength

The self-heated thermistor technique was used to measure the thermal conductivity and thermal diffusivity of biomaterials at low temperatures. Thermal standards were selected to calibrate the system at temperatures from −10°C to −70°C. The thermal probes were constructed with a convection barrier which eliminates convection inside liquid samples of low viscosity, without affecting the conductivity and diffusivity results. Using this technique, the thermal conductivity and diffusivity of two organ perfusates (HP5 and HP5 + 2M glycerol), one kidney phantom (a low ionic strength gel), as well as rabbit kidney cortex have been measured from −10°C to −70°C.

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