scholarly journals Thermal transport properties of decagonal quasicrystals and their approximants

2013 ◽  
Vol 1517 ◽  
Author(s):  
Petar Popčević ◽  
Ante Bilušić ◽  
Kristijan Velebit ◽  
Ana Smontara

ABSTRACTTransport properties (thermal conductivity, electrical resistivity and thermopower) of decagonal quasicrystal d-AlCoNi, and approximant phases Y-AlCoNi, o-Al13Co4, m-Al13Fe4, m-Al13(Fe,Ni)4 and T-AlMnFe have been reviewed. Among all presented alloys the stacking direction (periodic for decagonal quasicrystals) is the most conductive one for the charge and heat transport, and the in/out-of-plane anisotropy is much larger than the in-plane anisotropy. There is a strong relationship between periodicity length along stacking direction and anisotropy of transport properties in both quasicrystals and their approximants suggesting a decrease of the anisotropy with increasing number of stacking layers.

2001 ◽  
Vol 691 ◽  
Author(s):  
Donny W. Winkler ◽  
Terry M. Tritt ◽  
Robert Gagnon ◽  
J. Strom-Olsen

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.


RSC Advances ◽  
2021 ◽  
Vol 11 (39) ◽  
pp. 24456-24465
Author(s):  
Rapaka S. C. Bose ◽  
K. Ramesh

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.


2003 ◽  
Vol 793 ◽  
Author(s):  
Y. Amagai ◽  
A. Yamamoto ◽  
C. H. Lee ◽  
H. Takazawa ◽  
T. Noguchi ◽  
...  

ABSTRACTWe report transport properties of polycrystalline TMGa3(TM = Fe and Ru) compounds in the temperature range 313K<T<973K. These compounds exhibit semiconductorlike behavior with relatively high Seebeck coefficient, electrical resistivity, and Hall carrier concentrations at room temperature in the range of 1017- 1018cm−3. Seebeck coefficient measurements reveal that FeGa3isn-type material, while the Seebeck coefficient of RuGa3changes signs rapidly from large positive values to large negative values around 450K. The thermal conductivity of these compounds is estimated to be 3.5Wm−1K−1at room temperature and decreased to 2.5Wm−1K−1for FeGa3and 2.0Wm−1K−1for RuGa3at high temperature. The resulting thermoelectric figure of merit,ZT, at 945K for RuGa3reaches 0.18.


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

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


2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Jae-Yeol Hwang ◽  
Eun Sung Kim ◽  
Syed Waqar Hasan ◽  
Soon-Mok Choi ◽  
Kyu Hyoung Lee ◽  
...  

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.


1975 ◽  
Vol 53 (5) ◽  
pp. 486-497 ◽  
Author(s):  
J. G. Cook ◽  
M. J. Laubitz ◽  
M. P. Van der Meer

Data are presented for the thermal and electrical resistivity and thermoelectric power of two samples of Ca (having residual resistance ratios of 10 and 70) between 30 and 300 K. Large deviations from both Matthiessen's rule and the Wiedemann–Franz relationship are observed. The former are tentatively attributed to the presence of two distinct groups of carriers in Ca, and analyzed using the two band model. The latter deviations are interpreted as the effects of band structure. The thermoelectric power of Ca is large. In many respects the transport properties of Ca appear to be similar to those of the transition metals.


2017 ◽  
Vol 24 (03) ◽  
pp. 1750033
Author(s):  
F. MEYDANERI TEZEL ◽  
B. SAATÇI ◽  
M. ARI ◽  
S. DURMUŞ ACER ◽  
E. ALTUNER

The structural, surface and transport properties of Sn–Ag alloys were investigated by X-ray diffraction (XRD), radial heat flow, energy-dispersive X-ray (EDX) analysis, scanning electron microscopy (SEM) and four-point probe techniques. We observed that the samples had tetragonal crystal symmetry except for the pure Ag sample which had cubic crystal symmetry, and with the addition of Ag the cell parameters increased slightly. Smooth surfaces with a clear grain boundary for the samples were shown on the SEM micrographs. The grain sizes of pure Ag, [Formula: see text]-Sn and the formed Ag3Sn intermetallic compound phase for Sn–[Formula: see text] wt.% Ag [[Formula: see text], 3.5] binary alloys were determined to be 316[Formula: see text]nm, between 92[Formula: see text]nm and 80[Formula: see text]nm and between 36[Formula: see text]nm and 34[Formula: see text]nm, respectively. The values of electrical resistivity for pure Sn, pure Ag and Sn–[Formula: see text] wt.% Ag [[Formula: see text], 3.5] were obtained to be [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text][Formula: see text][Formula: see text]m at the temperature range of 300–450[Formula: see text]K, respectively. Thermal conductivity values of pure Sn and Sn–[Formula: see text] wt.% Ag [[Formula: see text], 3.5] binary alloys were found to be 60.60[Formula: see text]3.75, 69.00[Formula: see text]4.27 and 84.60[Formula: see text]5.24[Formula: see text]W/Km. These values slightly decreased with increasing temperature and increase with increasing of the Ag composition. Additionally, the temperature coefficients of thermal conductivity and electrical resistivity and the Lorenz numbers were calculated.


2014 ◽  
Vol 1619 ◽  
Author(s):  
P. Kalakonda ◽  
A. Casey ◽  
G. S. Iannacchione ◽  
G. Y. Georgiev ◽  
Y. Cabrera ◽  
...  

ABSTRACTA computational algorithm has been developed to simulate the transport properties of oriented and un-oriented thin film nanocomposites of isotactic Polypropylene (iPP) and carbon nanotubes (CNT) with increasing CNT concentration. Our goal is to be able to design materials with optimal properties using these simulations. We use a cellular automata approach in a Matlab 3-D array environment. The percolation threshold is reproduced in the simulations, matching experimental data. Upon percolation, the thermal transport in the films increases sharply, due to the large difference in the thermal conductivities of the CNTs and the polymer. To verify the simulation, the thin-film samples were sheared in the melt at 200C at 1 Hz in a Linkan microscope shearing hot stage. The thermal conductivity measurements were performed on the same cell arrangement with the transport perpendicular to the thin-film plane using a DC method. The thermal conductivity is higher for the un-sheared as compared to the sheared samples. Our cellular automata simulations provide information about the microstructuremacroscopic property relation in the thin film nanocomposites and can be extended to simulations of other important materials.


2003 ◽  
Vol 793 ◽  
Author(s):  
N. Sorloaica ◽  
A. L. Pope ◽  
D. W. Winkler ◽  
Terry M. Tritt ◽  
V. Keppens ◽  
...  

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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