Decoupling thermoelectric transport coefficients of Dirac semimetal Na2AgSb with intrinsically ultralow lattice thermal conductivity

2021 ◽  
pp. 100560
Author(s):  
Shihao Han ◽  
Zizhen Zhou ◽  
Caiyu Sheng ◽  
Rui Hu ◽  
Hongmei Yuan ◽  
...  
RSC Advances ◽  
2016 ◽  
Vol 6 (65) ◽  
pp. 60736-60740 ◽  
Author(s):  
Xin Guo ◽  
Jieming Qin ◽  
Xiaoling Lv ◽  
Le Deng ◽  
Xiaopeng Jia ◽  
...  

Doping In into a Bi2Te3 matrix can significantly transform textural features and decrease the lattice thermal conductivity.


2019 ◽  
Vol 1 (3) ◽  
Author(s):  
Shengying Yue ◽  
Hamid T. Chorsi ◽  
Manik Goyal ◽  
Timo Schumann ◽  
Runqing Yang ◽  
...  

2021 ◽  
Vol 104 (2) ◽  
Author(s):  
E. Lora da Silva ◽  
A. Leonardo ◽  
Tao Yang ◽  
M. C. Santos ◽  
R. Vilaplana ◽  
...  

2020 ◽  
Vol 10 (5) ◽  
pp. 602-609
Author(s):  
Adil H. Awad

Introduction: A new approach for expressing the lattice thermal conductivity of diatomic nanoscale materials is developed. Methods: The lattice thermal conductivity of two samples of GaAs nanobeam at 4-100K is calculated on the basis of monatomic dispersion relation. Phonons are scattered by nanobeam boundaries, point defects and other phonons via normal and Umklapp processes. Methods: A comparative study of the results of the present analysis and those obtained using Callaway formula is performed. We clearly demonstrate the importance of the utilised scattering mechanisms in lattice thermal conductivity by addressing the separate role of the phonon scattering relaxation rate. The formulas derived from the correction term are also presented, and their difference from Callaway model is evident. Furthermore their percentage contribution is sufficiently small to be neglected in calculating lattice thermal conductivity. Conclusion: Our model is successfully used to correlate the predicted lattice thermal conductivity with that of the experimental observation.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aastha Vasdev ◽  
Moinak Dutta ◽  
Shivam Mishra ◽  
Veerpal Kaur ◽  
Harleen Kaur ◽  
...  

AbstractA remarkable decrease in the lattice thermal conductivity and enhancement of thermoelectric figure of merit were recently observed in rock-salt cubic SnTe, when doped with germanium (Ge). Primarily, based on theoretical analysis, the decrease in lattice thermal conductivity was attributed to local ferroelectric fluctuations induced softening of the optical phonons which may strongly scatter the heat carrying acoustic phonons. Although the previous structural analysis indicated that the local ferroelectric transition temperature would be near room temperature in $${\text {Sn}}_{0.7}{\text {Ge}}_{0.3}{\text {Te}}$$ Sn 0.7 Ge 0.3 Te , a direct evidence of local ferroelectricity remained elusive. Here we report a direct evidence of local nanoscale ferroelectric domains and their switching in $${\text {Sn}}_{0.7}{\text {Ge}}_{0.3}{\text {Te}}$$ Sn 0.7 Ge 0.3 Te using piezoeresponse force microscopy(PFM) and switching spectroscopy over a range of temperatures near the room temperature. From temperature dependent (250–300 K) synchrotron X-ray pair distribution function (PDF) analysis, we show the presence of local off-centering distortion of Ge along the rhombohedral direction in global cubic $${\text {Sn}}_{0.7}{\text {Ge}}_{0.3}{\text {Te}}$$ Sn 0.7 Ge 0.3 Te . The length scale of the $${\text {Ge}}^{2+}$$ Ge 2 + off-centering is 0.25–0.10 Å near the room temperatures (250–300 K). This local emphatic behaviour of cation is the cause for the observed local ferroelectric instability, thereby low lattice thermal conductivity in $${\text {Sn}}_{0.7}{\text {Ge}}_{0.3}{\text {Te}}$$ Sn 0.7 Ge 0.3 Te .


Universe ◽  
2021 ◽  
Vol 7 (6) ◽  
pp. 203
Author(s):  
Peter Shternin ◽  
Isaac Vidaña

We consider transport properties of the hypernuclear matter in neutron star cores. In particular, we calculate the thermal conductivity, the shear viscosity, and the momentum transfer rates for npΣ−Λeμ composition of dense matter in β–equilibrium for baryon number densities in the range 0.1–1 fm−3. The calculations are based on baryon interactions treated within the framework of the non-relativistic Brueckner-Hartree-Fock theory. Bare nucleon-nucleon (NN) interactions are described by the Argonne v18 phenomenological potential supplemented with the Urbana IX three-nucleon force. Nucleon-hyperon (NY) and hyperon-hyperon (YY) interactions are based on the NSC97e and NSC97a models of the Nijmegen group. We find that the baryon contribution to transport coefficients is dominated by the neutron one as in the case of neutron star cores containing only nucleons. In particular, we find that neutrons dominate the total thermal conductivity over the whole range of densities explored and that, due to the onset of Σ− which leads to the deleptonization of the neutron star core, they dominate also the shear viscosity in the high density region, in contrast with the pure nucleonic case where the lepton contribution is always the dominant one.


2020 ◽  
Vol 161 ◽  
pp. 112004
Author(s):  
Hongyu Zhang ◽  
Jizhong Sun ◽  
Yingmin Wang ◽  
Thomas Stirner ◽  
Ali Y. Hamid ◽  
...  

2021 ◽  
Vol 130 (4) ◽  
pp. 045101
Author(s):  
Qi Zhong ◽  
Zhenhong Dai ◽  
Junping Wang ◽  
Yinchang Zhao ◽  
Sheng Meng

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