Intrinsic low thermal conductivity in weakly ionic rocksalt structures

Zhang, Yi; Dong, Jianjun; Kent, Paul; Yang, Jihui; Chen, Changfeng

doi:10.1103/physrevb.92.020301

Cited by 10 publications

(6 citation statements)

References 36 publications

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“…This model is accurate for simulating the lattice thermal conductivity of materials with relatively low Θ D , such as NaCl, NaI and PbTe, but for materials with higher Θ D (973 K), the high-temperature Slack model cannot simulate experimental work well. 30 To analyse κ L for high temperatures, Eucken 31 concluded on empirical grounds that many substances have the same κ L at the melting point T m , which appears to work well for materials with low melting points, but is futile for crystals melting above 500 K. On the basis of this, Keyes proposed a better approximation at high temperatures: 32…”

Section: Results and Discussion Approachmentioning

confidence: 99%

Contribution of point defects and nano-grains to thermal transport behaviours of oxide-based thermoelectrics

et al. 2016

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Point defects and nano-grains are very effective ways to control the thermal conductivity in oxide-based thermoelectrics. Here we use the optimised Debye-Callaway model to understand how the effect of point defects and nano-grains to reduce the thermal conductivity by inducing normal process and oxygen vacancy in oxide-based thermoelectrics. Our results reveal that this model can be effective to fit the experimental data of thermal conductivity in ZnO-, CaMnO 3 -, BiCuSeO-, SrTiO 3 -and In 2 O 3 -based systems, which indicate that the normal scattering process and the oxygen vacancy will make obvious contribution to the thermal conductivity as compared with alloy compounds system. These calculations also propose that it could be desirable to obtain higher ZT by controlling the concentration of oxygen vacancy in the nano-grained thermoelectric oxides.

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Section: Results and Discussion Approachmentioning

confidence: 99%

Contribution of point defects and nano-grains to thermal transport behaviours of oxide-based thermoelectrics

et al. 2016

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“…The brown triangle dashed line represents lattice thermal conductivities using the classical MD simulations with the Buckingham potential. 25 The empty triangle, square, and circle dashed lines represent the calculations with ab initio IFC, 21 DFPT, 71 and BTE, 72 respectively. The black stars are the results using the neuroevolution potential (NEP).…”

Section: Resultsmentioning

confidence: 99%

“…6), 71 phonon Boltzmann transport equations (BTE) with force constants from DFT (the pink circle dashed line in Fig. 6) 72 and the DFT-based anharmonic lattice dynamics (ALD) (the pink triangle dashed line in Fig. 6).…”

Section: Resultsmentioning

confidence: 99%

A machine learning methodology to investigate the lattice thermal conductivity of defected PbTe

et al. 2023

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“…[15][16][17] Recent theoretical reports mainly take alkali halides as models to verify the accuracy of the improved prediction of thermal conductivity, [18][19] but the inherent thermal transport of alkali halides is rarely concerned. [7,[20][21][22] Therefore, a systemic revisit to the thermal transport properties in alkali halides by stateof-art computational techniques is of urgent necessity.…”

Section: Introductionmentioning

confidence: 99%

Anomalous Thermal Conductivity Induced by High Dispersive Optical Phonons in Rubidium and Cesium Halides

Chang¹,

Yuan²,

Li³

et al. 2022

ES Energy Environ.

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Knowledge of lattice dynamics is essential for understanding the physical properties of materials and optimizing the performance for applications. Alkali halides (MX, M=Na, K, Rb, and Cs; X=Cl, Br, and I) have been widely recognized for their simple crystal structures and low thermal conductivities. At room temperature, the thermal conductivity (κ) of RbBr is nearly twice as large as that of RbCl and RbI, while the thermal conductivities of three compounds in CsX halides are comparable. These thermal conductivity trends with increased atomic mass are significantly different from the common sense that the thermal conductivity conventionally decreases with the increasing atomic mass and decreasing electronegativity difference. However, little attention has been paid to the microscopic mechanism of these anomalous thermal conductions in RbX and CsX. Here, we report a systematic investigation of the thermal transport properties in alkali halides by the Boltzmann transport equation based on first-principles calculations. The results show that the anomalous thermal conductivity trends of RbX and CsX mainly attribute to the disparity of optical phonons in each compound. The more dispersive the optical phonons, the greater their contribution to the thermal conductivity, and thus the thermal conductivities of compounds with heavier atoms are enhanced. The disparity of optical phonons originates from the mass difference in the compound. Our work offers deeper insight into the unusual phonon thermal transport phenomenon in alkali halides, and provides fundamental reference for rooting the thermal conductivities in related functional materials and finding novel materials with thermal conduction beyond the conventional cognition.

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Intrinsic low thermal conductivity in weakly ionic rocksalt structures

Cited by 10 publications

References 36 publications

Contribution of point defects and nano-grains to thermal transport behaviours of oxide-based thermoelectrics

Contribution of point defects and nano-grains to thermal transport behaviours of oxide-based thermoelectrics

A machine learning methodology to investigate the lattice thermal conductivity of defected PbTe

Anomalous Thermal Conductivity Induced by High Dispersive Optical Phonons in Rubidium and Cesium Halides

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