scholarly journals Enhanced Electron Heat Conduction in TaS3 1D Metal Wire

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4477
Author(s):  
Hojoon Yi ◽  
Jaeuk Bahng ◽  
Sehwan Park ◽  
Dang Xuan Dang ◽  
Wonkil Sakong ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Heat Conduction ◽  
Room Temperature ◽  
Lorenz Number ◽  
Conduction Path ◽  
Metallic Behavior ◽  
3Ω Method ◽  
Electron Heat ◽  
Peierls Transition

The 1D wire TaS3 exhibits metallic behavior at room temperature but changes into a semiconductor below the Peierls transition temperature (Tp), near 210 K. Using the 3ω method, we measured the thermal conductivity κ of TaS3 as a function of temperature. Electrons dominate the heat conduction of a metal. The Wiedemann–Franz law states that the thermal conductivity κ of a metal is proportional to the electrical conductivity σ with a proportional coefficient of L0, known as the Lorenz number—that is, κ=σLoT. Our characterization of the thermal conductivity of metallic TaS3 reveals that, at a given temperature T, the thermal conductivity κ is much higher than the value estimated in the Wiedemann–Franz (W-F) law. The thermal conductivity of metallic TaS3 was approximately 12 times larger than predicted by W-F law, implying L=12L0. This result implies the possibility of an existing heat conduction path that the Sommerfeld theory cannot account for.

Anisotropic Thermal Conductivity of a Si/Ge Quantum Dot Superlattice

2000 ◽  
Author(s):  
Theodorian Borca-Tasciuc ◽  
Weili Liu ◽  
Jianlin Liu ◽  
Kang L. Wang ◽  
Gang Chen
Keyword(s):  
Thermal Conductivity ◽  
Quantum Dots ◽  
Molecular Beam ◽  
Conductivity Measurements ◽  
Transport Models ◽  
3Ω Method ◽  
Superlattice Structure ◽  
Anisotropic Thermal Conductivity ◽  
Ge Quantum Dot

Abstract In this work, we present experimental results on the in-plane and cross-plane thermal conductivity characterization of a Si/Ge quantum-dots superlattice structure. The quantum-dots superlattice was grown by molecular-beam-epitaxy and self-organization. The anisotropic thermal conductivity measurements are performed by a differential two-wire 3ω method. The measured in-plane and cross-plane thermal conductivity values show a different temperature behavior. The results are compared and explained with heat transport models in superlattices.

Long-term Room Temperature Instability in Thermal Conductivity of InGaZnO Thin Films

MRS Advances ◽  
2016 ◽  
Vol 1 (22) ◽  
pp. 1631-1636 ◽  
Author(s):  
Boya Cui ◽  
D. Bruce Buchholz ◽  
Li Zeng ◽  
Michael Bedzyk ◽  
Robert P. H. Chang ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Room Temperature ◽  
Storage Time ◽  
Laser Deposition ◽  
Low Oxygen ◽  
X Ray Diffraction ◽  
3Ω Method ◽  
X Ray

ABSTRACTThe cross-plane thermal conductivities of InGaZnO (IGZO) thin films in different morphologies were measured on three occasions within 19 months, using the 3ω method at room temperature 300 K. Amorphous (a-), semi-crystalline (semi-c-) and crystalline (c-) IGZO films were grown by pulsed laser deposition (PLD), followed by X-ray diffraction (XRD) for evaluation of film quality and crystallinity. Semi-c-IGZO shows the highest thermal conductivity, even higher than the most ordered crystal-like phase. After being stored in dry low-oxygen environment for months, a drastic decrease of semi-c-IGZO thermal conductivity was observed, while the thermal conductivity slightly reduced in c-IGZO and remained unchanged in a-IGZO. This change in thermal conductivity with storage time can be attributed to film structural relaxation and vacancy diffusion to grain boundaries.

Modeling Heat Conduction Across Thermal Interface Materials With Micro-Particles

2008 ◽  
Author(s):  
C. Channy Wong
Keyword(s):  
Thermal Conductivity ◽  
Heat Conduction ◽  
Composite Materials ◽  
Effective Thermal Conductivity ◽  
Thermal Interface Materials ◽  
Conduction Path ◽  
Micro Particles ◽  
Mechanical And Electrical Properties ◽  
Interface Materials ◽  
Composite Polymeric Material

Different types of fillers with high electrical and thermal conductivities, e.g. graphite and alumina, have been added to adhesive polymers to create composite materials with improved mechanical and electrical properties. Previous modeling efforts have found that it is relatively difficult to predict the effective thermal conductivity of a composite polymeric material when incorporated with large volume content of fillers. We have performed comprehensive computational analysis that models the thermal contacts between fillers. This unique setup can capture the critical heat conduction path to obtain the effective thermal conductivity of the composite materials. Results of these predictions and its comparison with experimental data will be presented in this paper.

Ultra-Low Thermal Conductivity in Nanoscale Layered Oxides

2009 ◽  
Vol 132 (3) ◽  
Author(s):  
J. Alvarez-Quintana ◽  
Ll. Peralba-Garcia ◽  
J. L. Lábár ◽  
J. Rodríguez-Viejo
Keyword(s):  
Thermal Conductivity ◽  
Thermal Barrier Coatings ◽  
Room Temperature ◽  
Thermal Barrier ◽  
Layered Oxides ◽  
Barrier Coatings ◽  
3Ω Method ◽  
Nanometer Thickness ◽  
Intrinsic Thermal Conductivity ◽  
Strong Barrier

The cross-plane thermal conductivity of several nanoscale layered oxides SiO2/Y2O3, SiO2/Cr2O3, and SiO2/Al2O3, synthesized by e-beam evaporation was measured in the range from 30 K to 300 K by the 3ω method. Thermal conductivity attains values around 0.5 W/m K at room temperature in multilayer samples, formed by 20 bilayers of 10 nm SiO2/10 nm Y2O3, and as low as 0.16 W/m K for a single bilayer. The reduction in thermal conductivity is related to the high interface density, which produces a strong barrier to heat transfer rather than to the changes of the intrinsic thermal conductivity due to the nanometer thickness of the layers. We show that the influence of the first few interfaces on the overall thermal resistance is higher than the subsequent ones. Annealing the multilayered samples to 1100°C slightly increases the thermal conductivity due to changes in the microstructure. These results suggest a route to obtain suitable thermal barrier coatings for high temperature applications.

Anisotropic Thermal Conductivity of Superconducting Lanthanum Cuprate

1989 ◽  
Vol 169 ◽  
Author(s):  
D.T. Morelli ◽  
G.L. Doll ◽  
J.P. Heremans ◽  
H.P. Jenssen ◽  
A. Cassanho ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Heat Conduction ◽  
Copper Oxide ◽  
Heat Transport ◽  
Electron Scattering ◽  
Heat Conductivity ◽  
Room Temperature ◽  
Lattice Thermal Conductivity ◽  
Lanthanum Copper Oxide ◽  
Anisotropic Thermal Conductivity

AbstractThe thermal conductivities of superconducting, Sr-doped lanthanum copper oxide single crystals have been measured from room temperature to below 100 mK parallel and perpendicular to the copper oxide planes. While the results indicate that the heat conduction is strongly anisotropic, the data have been analyzed in terms of a modified Bardeen-Rickhayzen-Tewordt theory of lattice thermal conductivity. It is shown that while electron scattering plays an important role in limiting the in-plane heat conductivity, this scattering channel is masked by other mechanisms for heat transport across the planes.

Heat Conduction Through Walls During Fire

1961 ◽  
Vol 83 (4) ◽  
pp. 508-510 ◽  
Author(s):  
Lie Tiam Tjoan
Keyword(s):  
Thermal Conductivity ◽  
Heat Conduction ◽  
Temperature Rise ◽  
Room Temperature ◽  
Experimental Results ◽  
Standard Fire

An expression is given for the temperature rise of a wall exposed on one side to a standard fire. It appears that calculated and experimental results agree with each other when a theoretical thermal conductivity is assumed which is a power of the thermal conductivity at room temperature.

Crystalline-Amorphous Interface: Molecular Dynamics Simulation of Thermal Conductivity

2001 ◽  
Vol 703 ◽  
Author(s):  
Sebastian von Alfthan ◽  
Antti Kuronen ◽  
Kimmo Kaski
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Monte Carlo Simulation ◽  
Heat Conduction ◽  
Room Temperature ◽  
Simulation Method ◽  
Dynamics Simulation ◽  
Monte Carlo Simulation Method ◽  
Silicon System ◽  
Dynamics Simulations

ABSTRACTEffect of a crystalline-amorphous interface on heat conduction has been studied using atom-istic simulations of a silicon system. System with amorphous silicon was created using the bond-switching Monte Carlo simulation method and heat conduction near room temperature was studied by molecular dynamics simulations of this system.

Thermoelectric Properties of NaZn13-type Intermetallic Compounds

2003 ◽  
Vol 793 ◽  
Author(s):  
Y. Amagai ◽  
A. Yamamoto ◽  
C. H. Lee ◽  
H. Takazawa ◽  
T. Noguchi ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Seebeck Coefficient ◽  
Power Factor ◽  
Room Temperature ◽  
Total Thermal Conductivity ◽  
Electrical Measurements ◽  
Metallic Behavior ◽  
Large Power ◽  
Absolute Value ◽  
The Absolute

ABSTRACTWe report the electrical resistivity and the Seebeck coefficient of AZn13(A = Sr, Ba, and La) and LaCo13measured over a wide temperature range and their thermal conductivity measured at room temperature. The electrical measurements of AZn13and LaCo13above room temperature reveal that the compounds show good metallic behavior. We find that the absolute value of Seebeck coefficient for AZn13(A = Sr, Ba, and La) increases with increasing temperature, which is a typical metallic behavior and the absolute value is less than 3μVK−1at room temperature. Accordingly, the power factor of AZn13is quite low. Temperature dependence of the Seebeck coefficient for LaCo13is similar to that of Co. The absolute value of the Seebeck coefficient for LaCo13is high as a metallic conductor and approaches -30μVK−1at 500K, which leads LaCo13to large power factor of 1.8 × 10−3Wm−1K−2. We obtained lattice components of the thermal conductivity by subtracting electronic contributions from the total thermal conductivity. The electronic components of the thermal conductivity were estimated using Wiedemann-Frantz law assumingL(Lorentz number) is 2.45 × 10−8V2K−2. The thermal conductivities of the lattice components for AZn13(A = Sr, Ba, and La) and LaCo13with NaZn13type structure are about 10 Wm−1K−1, respectively. These values are high as compared with other thermoelectric materials.

scholarly journals Rapid Synthesis and Characterization of an Oxygen-Deficient Defect Perovskite La4BaCu5O13+δ Phase

ISRN Ceramics ◽  
2011 ◽  
Vol 2011 ◽  
pp. 1-4 ◽  
Author(s):  
Chikkadasappa Shivakumara
Keyword(s):  
Room Temperature ◽  
Structural Parameters ◽  
Combustion Method ◽  
Metallic Behavior ◽  
Refinement Method ◽  
Gel Combustion ◽  
Δ Phase ◽  
Gel Combustion Method ◽  
Temperature Resistivity

Oxygen-deficient defect perovskite La4BaCu5O13+δ phase has been synthesized by the nitrate-citrate gel combustion method at 950°C for 2 h. Structural parameters were refined by the Rietveld refinement method using room-temperature powder XRD data. The La4BaCu5O13+δ crystallizes in the tetragonal structure with space group P4/m (no. 83) and having the lattice parameters a=8.6508(1) Å and c=3.8606(2) Å, respectively. Oxygen content was determined by the iodometric titration. Low-temperature resistivity result reveals that La4BaCu5O13+δ compound exhibit metallic behavior up to 15 K.

Thermal Conductivity of Nanochanneled Alumina

2000 ◽  
Author(s):  
A. R. Kumar ◽  
D.-A. Achimov ◽  
T. Zeng ◽  
G. Chen
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Experimental Study ◽  
Heat Conduction ◽  
Room Temperature ◽  
Conduction Model ◽  
Heat Conduction Model ◽  
Anisotropic Heat Conduction ◽  
3Ω Technique

Abstract We present an experimental study on the thermal conductivity of anodized alumina with regular nanochannels. Thermal conductivity values in both directions parallel and perpendicular to the nanochannel axis are measured at room temperature using the 3ω technique. An anisotropic heat conduction model is developed to analyze the experimental data.

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