scholarly journals Reduction of Lattice Thermal Conductivity in PbTe Induced by Artificially Generated Pores

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Jae-Yeol Hwang ◽  
Eun Sung Kim ◽  
Syed Waqar Hasan ◽  
Soon-Mok Choi ◽  
Kyu Hyoung Lee ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Pore Structure ◽  
Transport Properties ◽  
Thermoelectric Materials ◽  
Thermal Transport ◽  
Lattice Thermal Conductivity ◽  
Phonon Scattering ◽  
Phonon Modes ◽  
Thermal Transport Properties

Highly dense pore structure was generated by simple sequential routes using NaCl and PVA as porogens in conventional PbTe thermoelectric materials, and the effect of pores on thermal transport properties was investigated. Compared with the pristine PbTe, the lattice thermal conductivity values of pore-generated PbTe polycrystalline bulks were significantly reduced due to the enhanced phonon scattering by mismatched phonon modes in the presence of pores (200 nm–2 μm) in the PbTe matrix. We obtained extremely low lattice thermal conductivity (~0.56 W m−1 K−1at 773 K) in pore-embedded PbTe bulk after sonication for the elimination of NaCl residue.

scholarly journals Formation of Dense Pore Structure by Te Addition in Bi0.5Sb1.5Te3: An Approach to Minimize Lattice Thermal Conductivity

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Syed Waqar Hasan ◽  
Hyeona Mun ◽  
Sang Il Kim ◽  
Jung Young Cho ◽  
Jong Wook Roh ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Pore Structure ◽  
Transport Properties ◽  
Power Factor ◽  
Thermal Transport ◽  
Lattice Thermal Conductivity ◽  
Phonon Scattering ◽  
Synergetic Effects ◽  
Spark Plasma ◽  
P Type

We herein report the electronic and thermal transport properties of p-type Bi0.5Sb1.5Te3polycrystalline bulks with dense pore structure. Dense pore structure was fabricated by vaporization of residual Te during the pressureless annealing of spark plasma sintered bulks of Te coated Bi0.5Sb1.5Te3powders. The lattice thermal conductivity was effectively reduced to the value of 0.35 W m−1 K−1at 300 K mainly due to the phonon scattering by pores, while the power factor was not significantly affected. An enhancedZTof 1.24 at 300 K was obtained in spark plasma sintered and annealed bulks of 3 wt.% Te coated Bi0.5Sb1.5Te3by these synergetic effects.

Thermal transport properties of monolayer MoSe2 with defects

2020 ◽  
Vol 22 (10) ◽  
pp. 5832-5838 ◽  
Author(s):  
Jiang-Jiang Ma ◽  
Jing-Jing Zheng ◽  
Wei-Dong Li ◽  
Dong-Hong Wang ◽  
Bao-Tian Wang
Keyword(s):  
Thermal Conductivity ◽  
Transport Properties ◽  
Thermal Transport ◽  
Lattice Thermal Conductivity ◽  
Thermal Transport Properties

The defects in monolayer MoSe2 have a significant effect on its lattice thermal conductivity.

scholarly journals Influence of Te Vacancies on the Thermoelectric Properties of n-type Cu0.008Bi2Te2.7-xSe0.3

2020 ◽  
Vol 58 (10) ◽  
pp. 721-727
Author(s):  
Yerim Yang ◽  
TaeWan Kim ◽  
Seokown Hong ◽  
Jiwoo An ◽  
Sang-il Kim
Keyword(s):  
Thermal Conductivity ◽  
Transport Properties ◽  
Point Defect ◽  
Thermoelectric Properties ◽  
Thermal Transport ◽  
Phonon Scattering ◽  
Band Model ◽  
Total Thermal Conductivity ◽  
Thermal Transport Properties ◽  
Callaway Model

In this study, we report the influence of Te vacancy formation on the thermoelectric properties of n-type Cu0.008Bi2Te2.7Se0.3 alloys, including their electronic and thermal transport properties. Te-deficient Cu0.008Bi2Te2.7-xSe0.3 (x = 0, 0.005, 0.01 and 0.02) samples were systematically synthesized and characterized. Regarding electronic transport properties, carrier concentration was increased with Te vacancies, while carrier mobility was maintained. As a result, the electrical conductivity significantly increased while the Seebeck coefficient reduced moderately, thus, the power factor was enhanced from 3.04 mW/mK<sup>2</sup> (pristine) to 3.22 mW/mK<sup>2</sup> (x = 0.02) at 300 K. Further analysis based on a single parabolic band model revealed that the weighted mobility of the conduction band increased, which is favorable for electron transport, as Te vacancies were generated. Regarding thermal transport properties, lattice thermal conductivity decreased with Te vacancies due to additional point defect phonon scattering, however, total thermal conductivity increased due to larger electronic contribution as Te vacancies increased. Analysis using the Debye-Callaway model suggests that the phonon scattering by the Te vacancies is as efficient as the substitution point defect scattering. Consequently, the thermoelectric figure of merit zT increased at all temperatures for x = 0.005 and 0.01. The maximum zT of 0.95 was achieved for Te-deficient Cu0.008Bi2Te2.69Se0.3 (x = 0.01) at 400 K.

Atomistic Simulations of Heat Transport in Carbon Nanotubes Effected by Temperature and Stretch Strain

2011 ◽  
Vol 320 ◽  
pp. 38-44 ◽  
Author(s):  
Qing Yuan Meng ◽  
Yu Fei Gao ◽  
Xian Qin
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Low Temperature ◽  
Transport Properties ◽  
Thermal Transport ◽  
Phonon Scattering ◽  
Quantum Effect ◽  
Axial Strain ◽  
Thermal Transport Properties ◽  
Dynamic Structures

Carbon nanotubes (CNTs) is a well thermal transport nano materials, however, the thermal conductivity of CNTs has not been well established, only a few groups had reported experimental data and the existed simulation results ranged widely. Specially, the conclusions in low temperature section and dynamic structures were not very clearly. In this paper, the methods based on phonon scattering theory were applied to explore the thermal transport properties CNTs. The investigation was carried out under the conditions of temperature and axial strain. In the consideration of quantum effect, the thermal conductivity increased linearly with the growth of temperature in low-temperature section, and began to decrease gradually when the temperature exceeded a definite value. If an axial strain was concerned, there was an increasing trend of thermal conductivity as the stretch strain increases. However, after the strain exceeded a particular value the thermal conductivity decreased significantly. In addition, the high frequency phonon peak in PDOS was found to be an important parameter in describing thermal transport properties of dynamic structures.

First-principles calculations of thermal transport properties in MoS2/MoSe2 bilayer heterostructure

2019 ◽  
Vol 21 (20) ◽  
pp. 10442-10448 ◽  
Author(s):  
Jiang-Jiang Ma ◽  
Jing-Jing Zheng ◽  
Xue-Liang Zhu ◽  
Peng-Fei Liu ◽  
Wei-Dong Li ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Transport Properties ◽  
First Principles ◽  
Thermal Transport ◽  
Lattice Thermal Conductivity ◽  
Van Der Waals ◽  
Van Der Waals Interaction ◽  
First Principles Calculations ◽  
Thermal Transport Properties

The van der Waals interaction in a MoS2/MoSe2 bilayer heterostructure has a significant effect on its lattice thermal conductivity.

Investigation of i-AlCuFe Quasicrystals and their ω and β Approximants as Thermoelectric Materials

2001 ◽  
Vol 691 ◽  
Author(s):  
P. N. Alboni ◽  
A. L. Pope ◽  
T. M. Tritt ◽  
A. R. Ross ◽  
C. Jenks ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Transport Properties ◽  
Thermoelectric Materials ◽  
Thermal Transport ◽  
Quasicrystalline Phase ◽  
Crystalline Phases ◽  
Low Thermal Conductivity ◽  
Thermal Transport Properties

ABSTRACTIn the search for new thermoelectric materials, quasicrystals have been investigated due to their inherently low thermal conductivity. Crystalline phases called approximants which are closely related to the quasicrystals, however, have largely been ignored. These approximants have similar structure, yet the periodicity of a crystal. In this paper, we have investigated an icosahedral i-AlCuFe quasicrystalline phase as well as two of its corresponding approximant phases (ω and β). Electrical and thermal transport properties of these materials are presented. The viability of the i-AlCuFe quasicrystalline system and the ω and β approximant phases as thermoelectric materials is discussed.

First-principles study of thermal transport properties in the two- and three-dimensional forms of Bi2O2Se

2019 ◽  
Vol 21 (21) ◽  
pp. 10931-10938 ◽  
Author(s):  
Xue-Liang Zhu ◽  
Peng-Fei Liu ◽  
Guofeng Xie ◽  
Bao-Tian Wang
Keyword(s):  
Thermal Conductivity ◽  
Transport Properties ◽  
First Principles ◽  
Thermal Transport ◽  
Lattice Thermal Conductivity ◽  
Three Dimensional ◽  
First Principles Study ◽  
Thermal Transport Properties

The intralayer opposite phonon vibrations in the monolayer Bi2O2Se greatly suppress the thermal transport and lead to lower lattice thermal conductivity than its bilayer and bulk forms.

scholarly journals Study of anisotropic thermal conductivity in textured thermoelectric alloys by Raman spectroscopy

RSC Advances ◽  
2021 ◽  
Vol 11 (39) ◽  
pp. 24456-24465
Author(s):  
Rapaka S. C. Bose ◽  
K. Ramesh
Keyword(s):  
Crystal Structure ◽  
Thermal Conductivity ◽  
Raman Spectroscopy ◽  
Transport Properties ◽  
Thermal Transport ◽  
Layered Crystal ◽  
Layered Crystal Structure ◽  
Thermal Transport Properties ◽  
Anisotropic Thermal Conductivity ◽  
P Type

Polycrystalline p-type Sb1.5Bi0.5Te3 (SBT) and n-type Bi2Te2.7Se0.3 (BTS) compounds possessing layered crystal structure show anisotropic electronic and thermal transport properties.

Annealing Studies of Re Doped AlPdMn Quasicrystals

2001 ◽  
Vol 691 ◽  
Author(s):  
Donny W. Winkler ◽  
Terry M. Tritt ◽  
Robert Gagnon ◽  
J. Strom-Olsen
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Transport Properties ◽  
Thermal Transport ◽  
Amorphous Materials ◽  
Annealed Sample ◽  
Annealing Conditions ◽  
Thermal Transport Properties ◽  
The Relationship

ABSTRACTQuasicrystals have properties associated with both crystalline and amorphous materials. These properties appear to be sensitive to both composition and annealing conditions. Therefore, it is important to investigate the influence of the microstructure on the electrical and thermal transport properties of quasicrystals. AlPdMn quasicrystal samples were prepared with various levels of Re substituted for the Mn (Al70Pd20Mn10−XReX) and then subjected to different annealing conditions. Electrical resistivity, thermopower and thermal conductivity were measured on each as grown and annealed sample over a broad range of temperature, 10 K < T < 300 K. The relationship between the electrical and thermal transport properties and microstructure will be presented and discussed.

Evidence of a Order-Disorder Transition in the Crystalline Phase of Cd6Yb, 1/1 cubic approximant of icosahedral Cd 5.7 Yb

2003 ◽  
Vol 793 ◽  
Author(s):  
N. Sorloaica ◽  
A. L. Pope ◽  
D. W. Winkler ◽  
Terry M. Tritt ◽  
V. Keppens ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Temperature Dependence ◽  
Transport Properties ◽  
Crystalline Phase ◽  
Thermal Transport ◽  
Hysteretic Behavior ◽  
Disorder Transition ◽  
Temperature Range ◽  
Thermal Transport Properties

ABSTRACTThe electrical and thermal transport properties (electrical resistivity, thermopower, heat capacity and thermal conductivity) of the crystalline phase of the binary Cd6Yb system has been measured over a temperature range from 10 K to 300 K. Evidence for a phase transition in Cd6Yb is observed in the electrical transport properties with distinct changes in the temperature dependence of the resistivity and thermopower around T ≈ 110K. An anomaly in the heat capacity and a thermal conductivity is also observed at this same temperature. Hysteretic behavior is not evident in the temperature dependence of any of the electrical and thermal transport properties. In addition, the elastic properties using resonant ultrasound (RUS) techniques have been investigated over a similar temperature range. A large “resonance dip” is observed in the RUS data at T ≈ 110K, which is indicative of some type of structural change in the crystalline material at this temperature. These data will be presented and discussed in context of the undergoes reversible order-disorder transition in the 1/1 cubic approximant at about 110 K, which makes the system very interesting compared to the quasicrystal phase Cd5.7Yb

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