Thermal Conductivity of Metals

Uher, Ctirad

doi:10.1007/0-387-26017-x_2

Cited by 55 publications

(49 citation statements)

References 115 publications

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“…(10), see based on fitting a few experimental data points to k = A + BT −1 , where A and B are constants presumed to represent different mechanisms. 42,43 A derivation was neither provided in these early works nor subsequently 2,3,5,44,45 to the best of our knowledge. The lack of an explicit derivation during the crucial period when quantum mechanics was initially applied to the electron prevented critical analysis of Eq.…”

Section: Purpose Of the Present Studymentioning

confidence: 96%

“…Both phonons and electrons diffuse heat in a metal, as first proposed by Koenigsberger. 1 Modern analyses of bulk thermal conductivity measurements of metals assume that a simple sum pertains 3,5,18 :…”

Section: Purpose Of the Present Studymentioning

confidence: 99%

“…[3][4][5] Electrons have a very low heat capacity but high speeds (near the Fermi velocity) which are thought to compensate during heat transfer. Both properties stem from the Pauli exclusion principle, which only allows electrons near the Fermi energy to be promoted upon receipt of small amounts of heat energy.…”

Section: Introductionmentioning

confidence: 99%

“…Electrons are considered to dominate heat conduction in most metals. [2][3][4][5][6][7][8] However, experimental data and theoretical analyses of k show that the phononic (lattice) component is substantial in many transition metals, 18 particularly iron, 19 and roughly equals the contribution from electrons in impure metals or disordered alloys. 5 Ambiguities exist because proportions of the lattice (lat) and electronic (ele) contributions to k meas have been derived from models 5 rather than by experimentally isolating either of these components.…”

Section: Introductionmentioning

confidence: 99%

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Isolating lattice from electronic contributions in thermal transport measurements of metals and alloys above ambient temperature and an adiabatic model

Criss

Hofmeister²

2017

Int. J. Mod. Phys. B

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From femtosecond spectroscopy (fs-spectroscopy) of metals, electrons and phonons reequilibrate nearly independently, which contrasts with models of heat transfer at ordinary temperatures (T > 100 K). These electronic transfer models only agree with thermal conductivity (k) data at a single temperature, but do not agree with thermal diffusivity (D) data. To address the discrepancies, which are important to problems in solid state physics, we separately measured electronic (ele) and phononic (lat) components of D in many metals and alloys over ∼290-1100 K by varying measurement duration and sample length in laser-flash experiments. These mechanisms produce distinct diffusive responses in temperature versus time acquisitions because carrier speeds (u) and heat capacities (C) differ greatly. Electronic transport of heat only operates for a brief time after heat is applied because u is high. High D ele is associated with moderate T , long lengths, low electrical resistivity, and loss of ferromagnetism. Relationships of D ele and D lat with physical properties support our assignments. Although k ele reaches ∼20 × k lat near 470 K, it is transient. Combining previous data on u with each D This is an Open Access article published by World Scientific Publishing Company. It is distributed under the terms of the https://creativecommons.org/licenses/by/4.0Creative Commons Attribution 4.0 (CC-BY) License. Further distribution of this work is permitted, provided the original work is properly cited. * E. M. Criss is an employee of Panasonic Avionics Corporation, but prepared this paper independent of his employment and without use of information, resources, or other support from Panasonic Avionics Corporation.† Corresponding author. provides mean free paths and lifetimes that are consistent with ∼298 K fs-spectroscopy, and new values at high T . Our findings are consistent with nearly-free electrons absorbing and transmitting a small fraction of the incoming heat, whereas phonons absorb and transmit the majority. We model time-dependent, parallel heat transfer under adiabatic conditions which is one-dimensional in solids, as required by thermodynamic law. For noninteracting mechanisms, k ∼ = ΣC i k i ΣC i /(ΣC 2 i ). For metals, this reduces to k = k lat above ∼20 K, consistent with our measurements, and shows that Meissner's equation (k ∼ = k lat + k ele ) is invalid above ∼20 K. For one mechanism with multiple, interacting carriers, k ∼ = ΣC i k i /(ΣC i ). Thus, certain dynamic behaviors of electrons and phonons in metals have been misunderstood. Implications for theoretical models and technological advancements are briefly discussed.

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Section: Purpose Of the Present Studymentioning

confidence: 96%

Section: Purpose Of the Present Studymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Isolating lattice from electronic contributions in thermal transport measurements of metals and alloys above ambient temperature and an adiabatic model

Criss

Hofmeister²

2017

Int. J. Mod. Phys. B

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“…Thermal conductivity is well known to be strongly dependent on impurities and microstructural imperfections [16,28,32]. Both aspects are modified by heat treatment and thus a measurable impact on thermal conductivity of alloyed martensitic steels can be expected.…”

Section: Quenched Conditionsmentioning

confidence: 99%

The influence of heat treatment and resulting microstructures on the thermophysical properties of martensitic steels

et al. 2013

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This research study investigates the influence of heat treatment on the thermal conductivities of three different tool steels at room temperature. The results reveal not only that tempering plays a decisive role in their thermophysical properties, but also that the changes in thermal conductivity due to heat treatment are dependent on the degree of alloying. Isobaric heat capacities c p are found to be less dependent on heat treatment than thermal diffusivities a. The results are discussed with respect to the resulting microstructures and, for high-tempered conditions, under consideration of Calphad calculations. The results are relevant for the thermal design of tools, in particular, for tailored tempering of tools used for press hardening.

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Emerging Solid–State Thermal Switching Materials

Jia,

Li,

Chen

et al. 2024

Adv Funct Materials

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Growing technical demand for thermal management stems from the pursuit of high–efficient energy utilization and the reuse of wasted thermal energy, which necessitates the manipulation of heat flow with electronic analogs to improve device performance. Here, recent experimental progress is reviewed for thermal switching materials, aiming to achieve all–solid–state thermal switches, which are an enabling technology for solid–state thermal circuits. Moreover, the current understanding for discovering thermal switching materials is reshaped from the aspect of heat conduction mechanisms under external controls. Furthermore, current challenges and future perspectives are provided to highlight new and emerging directions for materials discovery in this continuously evolving field.

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Thermal Conductivity of Metals

Cited by 55 publications

References 115 publications

Isolating lattice from electronic contributions in thermal transport measurements of metals and alloys above ambient temperature and an adiabatic model

Isolating lattice from electronic contributions in thermal transport measurements of metals and alloys above ambient temperature and an adiabatic model

The influence of heat treatment and resulting microstructures on the thermophysical properties of martensitic steels

Emerging Solid–State Thermal Switching Materials

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