Experimental observation of hydrodynamic-like behavior in 3D topological semimetal ZrTe5

Abstract Hydrodynamic fluidity in condensed matter physics has been experimentally demonstrated only in a limited number of compounds because of the stringent conditions that must be satisfied. Herein, we demonstrate the existence of hydrodynamic-like properties driven by the collective excitation of the Dirac fluid in the three-dimensional topological semimetal ZrTe5. By measuring the electrical and thermal properties in a wide temperature range, we find a regime satisfying phononic hydrodynamic-like characteristics with two representative experimental evidences: a faster evolution of the thermal conductivity than in the ballistic regime and the existence of a local maximum of the effective mean free path. In contrast to phononic hydrodynamics, the Wiedemann-Franz law is violated by about a factor of 100. Moreover, phonon-dragged anomalies are observed, which serve as a signature of the Dirac fluidity in this system.

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Thermal Design of Highly-Efficient Thermoelectric Materials With Atomic-Scale Three-Dimensional Phononic Crystals

Volume 10: Mechanics of Solids and Structures, Parts A and B ◽

10.1115/imece2007-43538 ◽

2007 ◽

Author(s):

Jean-Numa Gillet ◽

Yann Chalopin ◽

Sebastian Volz

Keyword(s):

Thermal Conductivity ◽

Bulk Material ◽

Phononic Crystal ◽

Three Dimensional ◽

Mean Free Path ◽

Dispersion Curves ◽

Phononic Crystals ◽

Thermal Design ◽

Atomic Scale ◽

Thermal Insulating

Owing to their thermal insulating properties, superlattices have been extensively studied. A breakthrough in the performance of thermoelectric devices was achieved by using superlattice materials. The problem of those nanostructured materials is that they mainly affect heat transfer in only one direction. In this paper, the concept of canceling heat conduction in the three spatial directions by using atomic-scale three-dimensional (3D) phononic crystals is explored. A period of our atomic-scale 3D phononic crystal is made up of a large number of diamond-like cells of silicon atoms, which form a square supercell. At the center of each supercell, we substitute a smaller number of Si diamond-like cells by other diamond-like cells, which are composed of germanium atoms. This elementary heterostructure is periodically repeated to form a Si/Ge 3D nanostructure. To obtain different atomic configurations of the phononic crystal, the number of Ge diamond-like cells at the center of each supercell can be varied by substitution of Si diamond-like cells. The dispersion curves of those atomic configurations can be computed by lattice dynamics. With a general equation, the thermal conductivity of our atomic-scale 3D phononic crystal can be derived from the dispersion curves. The thermal conductivity can be reduced by at least one order of magnitude in an atomic-scale 3D phononic crystal compared to a bulk material. This reduction is due to the decrease of the phonon group velocities without taking into account that of the phonon average mean free path.

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Size Effect on the Thermal Conductivity of Thin Metallic Films Investigated by Scanning Joule Expansion Microscopy

Journal of Heat Transfer ◽

10.1115/1.2928014 ◽

2008 ◽

Vol 130 (8) ◽

Cited By ~ 25

Author(s):

Siva P. Gurrum ◽

William P. King ◽

Yogendra K. Joshi ◽

Koneru Ramakrishna

Keyword(s):

Thermal Conductivity ◽

Size Effect ◽

Three Dimensional ◽

Mean Free Path ◽

Local Temperature ◽

Metallic Films ◽

Dielectric Interface ◽

Dimensional Finite Element ◽

Three Dimensional Finite Element ◽

Electron Mean Free Path

A technique to extract in-plane thermal conductivity of thin metallic films whose thickness is comparable to electron mean free path is described. Microscale constrictions were fabricated into gold films of thicknesses 43nm and 131nm. A sinusoidal voltage excitation across the constriction results in a local temperature rise. An existing technique known as scanning joule expansion microscopy, measures the corresponding periodic thermomechanical expansion with a 10nm resolution and determines the local temperature gradient near the constriction. A three-dimensional finite-element simulation of the frequency-domain heat transfer fits the in-plane thermal conductivity to the measured data, finding thermal conductivities of 82±7.7W∕mK for the 43nm film and 162±16.7W∕mK for the 131nm film, at a heating frequencies of 100kHz and 90kHz, respectively. These values are significantly smaller than the bulk thermal conductivity value of 318W∕mK for gold, showing the electron size effect due to the metal-dielectric interface and grain boundary scattering. The obtained values are close to the thermal conductivity values, which are derived from electrical conductivity measurements after using the Wiedemann–Franz law. Because the technique does not require suspended metal bridges, it captures true metal-dielectric interface scattering characteristics. The technique can be extended to other films that can carry current and result in Joule heating, such as doped single crystal or polycrystalline semiconductors.

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Exact Solution of Heat Conduction in a Two-Domain Parallelepiped With an Orthotropic Layer and Its Application to the Estimation of the Three-Dimensional Thermal Conductivity Tensor and Volumetric Heat Capacity of the Orthotropic Layer

Heat Transfer, Volume 6 ◽

10.1115/imece2002-32424 ◽

2002 ◽

Author(s):

Cuauhtemoc Aviles-Ramos

Keyword(s):

Thermal Conductivity ◽

Heat Flux ◽

Exact Solution ◽

Heat Capacity ◽

Thermal Properties ◽

Hybrid Algorithm ◽

Three Dimensional ◽

Volumetric Heat Capacity ◽

Parameter Estimation Problem ◽

Orthotropic Layer

The three-dimensional exact solution of heat conduction in a two-layer composite is found applying the method of separation of variables. One layer is orthotropic and the other layer is isotropic. This solution is used to calculate sensitivity coefficients with respect to the thermophysical properties of the orthotropic layer at fourteen thermocouple locations. Numerical experiments are carried out to solve a parameter estimation problem that involves the estimation of the thermal conductivities in the x-, y-, and z-directions, the volumetric heat capacity of the orthotropic layer, the effective thermal conductivity of the isotropic layer, and the heat flux input. The exact solution is used to generate temperature readings at fourteen thermocouple locations. First, the parameter estimation problem is solved using the exact temperatures and a hybrid algorithm to estimate the thermal properties and the heat flux. Second, random noise is added to the exact temperatures and the thermal properties and heat flux are estimated using the same hybrid algorithm. It is found that when using the exact temperatures, the minimized quadratic functional has a value of 2.4×10−16 (°C)2 and the estimated properties agree to the ninth decimal place with the “exact” properties.

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Collinear Deflection Method for the Measurement of Thermal Conductivity of Transparent Single Layer Anisotropic Material

Applied Sciences ◽

10.3390/app9081522 ◽

2019 ◽

Vol 9 (8) ◽

pp. 1522

Author(s):

Moojoong Kim ◽

Kuentae Park ◽

Gwantaek Kim ◽

Jaisuk Yoo ◽

Dong-Kwon Kim ◽

...

Keyword(s):

Thermal Conductivity ◽

Thermal Properties ◽

Anisotropic Material ◽

Crystal Orientation ◽

Three Dimensional ◽

Single Layer ◽

Anisotropic Materials ◽

Analysis Model ◽

Anisotropic Thermal Conductivity ◽

Property Measurement

Transparent anisotropic materials have garnered attention along with the growth of the semiconductor and display industries. Transparent anisotropic materials have the characteristic of varying electrical, optical, and thermal properties based on their crystal orientation, and many studies are being conducted on this topic. In order to utilize transparent anisotropic materials properly, thermal properties such as thermal conductivity are essentially required. However, due to the limitations of the existing thermal property measurement methods for transparent anisotropic materials, it is difficult to provide the thermal properties of transparent anisotropic materials. To address this problem, a transparent anisotropic collinear method capable of measuring the effective thermal conductivity of a transparent anisotropic material according to its crystal orientation is proposed in this paper. To this end, the internal temperature distribution of a transparent anisotropic material and the phase delay of the probe beam were theoretically derived through a numerical analysis model that uses a three-dimensional heat conduction equation. This model was applied to anisotropic thermal conductivity with orthorhombic structure. To verify the proposed method of measuring the thermal conductivity of a transparent anisotropic material, the thermal properties of 3 mm-thick A-plane sapphire glass were measured and compared with those of the existing literature. It was confirmed that the absolute errors were less than about 4 W/mk.

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Structure and Thermoelectric Properties of New Quaternary Tin and Lead Bismuth Selenides, K1+xM4-2xBi7+xSe15 (M = Sn, Pb) and K1+xSn5-xBi11+xSe22

MRS Proceedings ◽

10.1557/proc-626-z8.4 ◽

2000 ◽

Vol 626 ◽

Author(s):

Antje Mrotzek ◽

Kyoung-Shin Choi ◽

Duck-Young Chung ◽

Melissa A. Lane ◽

John R. Ireland ◽

...

Keyword(s):

Thermal Conductivity ◽

Single Crystal ◽

Thermoelectric Properties ◽

Three Dimensional ◽

Structure Type ◽

Narrow Gap ◽

Low Thermal Conductivity ◽

Seebeck Coefficients ◽

Metal Atoms ◽

Anionic Framework

ABSTRACTWe present the structure and thermoelectric properties of the new quaternary selenides K1+xM4–2xBi7+xSe15 (M = Sn, Pb) and K1-xSn5-xBi11+xSe22. The compounds K1+xM4-2xBi7+xSe15 (M= Sn, Pb) crystallize isostructural to A1+xPb4-2xSb7+xSe15 with A = K, Rb, while K1-xSn5-xBi11+xSe22 reveals a new structure type. In both structure types fragments of the Bi2Te3-type and the NaCl-type are connected to a three-dimensional anionic framework with K+ ions filled tunnels. The two structures vary by the size of the NaCl-type rods and are closely related to β-K2Bi8Se13 and K2.5Bi8.5Se14. The thermoelectric properties of K1+xM4-2xBi7+xSe15 (M = Sn, Pb) and K1-xSn5-xBi11+xSe22 were explored on single crystal and ingot samples. These compounds are narrow gap semiconductors and show n-type behavior with moderate Seebeck coefficients. They have very low thermal conductivity due to an extensive disorder of the metal atoms and possible “rattling” K+ ions.

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Thermal Characterization of Carbon-Carbon Composites

Volume 10: Heat and Mass Transport Processes, Parts A and B ◽

10.1115/imece2011-64061 ◽

2011 ◽

Author(s):

Messiha Saad ◽

Darryl Baker ◽

Rhys Reaves

Keyword(s):

Thermal Conductivity ◽

Thermal Properties ◽

Thermal Diffusivity ◽

Specific Heat ◽

Critical Role ◽

Carbon Composite ◽

Flash Method ◽

Carbon Composites ◽

Energy Storage Devices ◽

Graphitized Carbon

Thermal properties of materials such as specific heat, thermal diffusivity, and thermal conductivity are very important in the engineering design process and analysis of aerospace vehicles as well as space systems. These properties are also important in power generation, transportation, and energy storage devices including fuel cells and solar cells. Thermal conductivity plays a critical role in the performance of materials in high temperature applications. Thermal conductivity is the property that determines the working temperature levels of the material, and it is an important parameter in problems involving heat transfer and thermal structures. The objective of this research is to develop thermal properties data base for carbon-carbon and graphitized carbon-carbon composite materials. The carbon-carbon composites tested were produced by the Resin Transfer Molding (RTM) process using T300 2-D carbon fabric and Primaset PT-30 cyanate ester. The graphitized carbon-carbon composite was heat treated to 2500°C. The flash method was used to measure the thermal diffusivity of the materials; this method is based on America Society for Testing and Materials, ASTM E1461 standard. In addition, the differential scanning calorimeter was used in accordance with the ASTM E1269 standard to determine the specific heat. The thermal conductivity was determined using the measured values of their thermal diffusivity, specific heat, and the density of the materials.

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Testing a Gypsum Composite Based on Raw Gypsum with a Direct Admixture of Paraffin and Polymer to Improve Thermal Properties

Materials ◽

10.3390/ma14123241 ◽

2021 ◽

Vol 14 (12) ◽

pp. 3241

Author(s):

Krzysztof Powała ◽

Andrzej Obraniak ◽

Dariusz Heim

Keyword(s):

Thermal Conductivity ◽

Heat Capacity ◽

Thermal Properties ◽

Phase Change ◽

Large Scale ◽

Building Materials ◽

Residential Buildings ◽

Energy Performance ◽

Polymer Content ◽

Volumetric Heat Capacity

The implemented new legal regulations regarding thermal comfort, the energy performance of residential buildings, and proecological requirements require the design of new building materials, the use of which will improve the thermal efficiency of newly built and renovated buildings. Therefore, many companies producing building materials strive to improve the properties of their products by reducing the weight of the materials, increasing their mechanical properties, and improving their insulating properties. Currently, there are solutions in phase-change materials (PCM) production technology, such as microencapsulation, but its application on a large scale is extremely costly. This paper presents a solution to the abovementioned problem through the creation and testing of a composite, i.e., a new mixture of gypsum, paraffin, and polymer, which can be used in the production of plasterboard. The presented solution uses a material (PCM) which improves the thermal properties of the composite by taking advantage of the phase-change phenomenon. The study analyzes the influence of polymer content in the total mass of a composite in relation to its thermal conductivity, volumetric heat capacity, and diffusivity. Based on the results contained in this article, the best solution appears to be a mixture with 0.1% polymer content. It is definitely visible in the tests which use drying, hardening time, and paraffin absorption. It differs slightly from the best result in the thermal conductivity test, while it is comparable in terms of volumetric heat capacity and differs slightly from the best result in the thermal diffusivity test.

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Scattering Mechanisms and Suppression of Bipolar Diﬀusion Eﬀect in Bi2Te2.85Se0.15Ix Compounds

Materials ◽

10.3390/ma14061564 ◽

2021 ◽

Vol 14 (6) ◽

pp. 1564

Author(s):

Jin Hee Kim ◽

Song Yi Back ◽

Jae Hyun Yun ◽

Ho Seong Lee ◽

Jong-Soo Rhyee

Keyword(s):

Thermal Conductivity ◽

Carrier Concentration ◽

Hall Mobility ◽

Lattice Distortion ◽

Phonon Scattering ◽

Iodine Concentration ◽

Mean Free Path ◽

Bandgap Energy ◽

Diffusion Effect ◽

Iodine Doping

We investigated the anisotropic thermoelectric properties of the Bi2Te2.85Se0.15Ix (x = 0.0, 0.1, 0.3, 0.5 mol.%) compounds, synthesized by ball-milling and hot-press sintering. The electrical conductivities of the Bi2Te2.85Se0.15Ix were significantly improved by the increase of carrier concentration. The dominant electronic scattering mechanism was changed from the mixed (T ≤ 400 K) and ionization scattering (T ≥ 420 K) for pristine compound (x = 0.0) to the acoustic phonon scattering by the iodine doping. The Hall mobility was also enhanced with the increasing carrier concentration. The enhancement of Hall mobility was caused by the increase of the mean free path of the carrier from 10.8 to 17.7 nm by iodine doping, which was attributed to the reduction of point defects without the meaningful change of bandgap energy. From the electron diffraction patterns, a lattice distortion was observed in the iodine doped compounds. The modulation vector due to lattice distortion increased with increasing iodine concentration, indicating the shorter range lattice distortion in real space for the higher iodine concentration. The bipolar thermal conductivity was suppressed, and the effective masses were increased by iodine doping. It suggests that the iodine doping minimizes the ionization scattering giving rise to the suppression of the bipolar diffusion effect, due to the prohibition of the BiTe1 antisite defect, and induces the lattice distortion which decreases lattice thermal conductivity, resulting in the enhancement of thermoelectric performance.

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Ballistic Heat Transport in Nanocomposite: The Role of the Shape and Interconnection of Nanoinclusions

Nanomaterials ◽

10.3390/nano11081982 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1982

Author(s):

Paul Desmarchelier ◽

Alice Carré ◽

Konstantinos Termentzidis ◽

Anne Tanguy

Keyword(s):

Thermal Conductivity ◽

Molecular Dynamics ◽

Molecular Dynamics Simulations ◽

Free Path ◽

Mean Free Path ◽

Strong Increase ◽

Moderate Increase ◽

Energy Propagation ◽

The Mean ◽

Dynamics Simulations

In this article, the effect on the vibrational and thermal properties of gradually interconnected nanoinclusions embedded in an amorphous silicon matrix is studied using molecular dynamics simulations. The nanoinclusion arrangement ranges from an aligned sphere array to an interconnected mesh of nanowires. Wave-packet simulations scanning different polarizations and frequencies reveal that the interconnection of the nanoinclusions at constant volume fraction induces a strong increase of the mean free path of high frequency phonons, but does not affect the energy diffusivity. The mean free path and energy diffusivity are then used to estimate the thermal conductivity, showing an enhancement of the effective thermal conductivity due to the existence of crystalline structural interconnections. This enhancement is dominated by the ballistic transport of phonons. Equilibrium molecular dynamics simulations confirm the tendency, although less markedly. This leads to the observation that coherent energy propagation with a moderate increase of the thermal conductivity is possible. These findings could be useful for energy harvesting applications, thermal management or for mechanical information processing.

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