Cerium Doped Bismuth Antimony

2012 ◽  
Vol 1456 ◽  
Author(s):  
Kevin C. Lukas ◽  
Huaizhou Zhao ◽  
Ryan L. Stillwell ◽  
Zhifeng Ren ◽  
Cyril P. Opeil

ABSTRACTBismuth-Antimony alloys have been shown to have high ZT values below room temperature, especially for single crystals. For polycrystalline samples, impurity doping and magnetic field have proven to be powerful tools in the search for understanding and improving thermoelectric performance. Nanopolycrystalline Bi0.88Sb0.12 doped with 0.05, 0.5 and 3 % Ce were prepared by ball milling and dc hot pressing techniques. Electrical resistivity, Seebeck coefficient, thermal conductivity, carrier concentration, mobility, and magnetization are measured in a temperature range of 5-350 K and in magnetic fields up to 9 Tesla. The effects of Ce doping on the thermoelectric properties of Bi0.88Sb0.12 in zero magnetic field are discussed.

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.


2011 ◽  
Vol 25 (22) ◽  
pp. 1829-1838 ◽  
Author(s):  
Q. R. HOU ◽  
B. F. GU ◽  
Y. B. CHEN ◽  
Y. J. HE

Phonon-drag effect usually occurs in single crystals at very low temperatures (10–200 K). Strong phonon-drag effect is observed in ultra-thin β- FeSi 2 films at around room temperature. The Seebeck coefficient of a 23 nm-thick β- FeSi 2 film can reach -1.375 mV/K at 343 K. However, the thermoelectric power factor of the film is still small, only 0.42×10-3 W/m-K2, due to its large electrical resistivity. When a 27 nm-thick MnSi 1.7 film with low electrical resistivity is grown on it, the thermoelectric power factor of the MnSi 1.7 film can reach 1.5×10-3 W/m-K2 at around room temperature. This value is larger than that of bulk MnSi 1.7 material in the same temperature range.


2007 ◽  
Vol 124-126 ◽  
pp. 1019-1022 ◽  
Author(s):  
K.W. Jang ◽  
Il Ho Kim ◽  
Jung Il Lee ◽  
Good Sun Choi

Non-stoichiometric Zn4-xSb3 compounds with x=0~0.5 were prepared by vacuum melting at 1173K and annealing solidified ingots at 623K. Electrical resistivity and Seebeck coefficient at 450K increased from 1.8cm and 145K-1 for Zn4Sb3(x=0) to 56.2cm 350K-1 for Zn3.5Sb3(x=0.5) due to the decrease of the carrier concentration. Hall mobility and carrier concentration was 31.5cm2V-1s-1 and 1.32X1020cm-3 for Zn4Sb3 and 70cm2V-1s-1 and 2.80X1018cm-3 for Zn3.5Sb3. Electrical resistivity of Zn4-xSb3 with x=0~0.2 showed linearly increasing temperature dependence, whereas those of Zn4-xSb3 with x=0.3~0.5 above 450 K tended to decrease. Thermal conductivity of Zn4Sb3 was 8.5mWcm-1K-1 at room temperature and that of Zn4-xSb3 with x≥0.3 was around 11mWcm-1K-1. Maximum ZT of Zn4Sb3 was obtained around 1.3 at 600K. Zn4Sb3 with x=0.3~0.5 showed very small value of ZT=0.2~0.3.


2013 ◽  
Vol 802 ◽  
pp. 223-226 ◽  
Author(s):  
Sunti Phewphong ◽  
Tosawat Seetawan

The PbTe has been prepared by pressing and annealing method in argon atmosphere. The PbTe sample was obtained single phase and cubic structure. The Seebeck coefficient, the electrical resistivity, thermal conductivity measured by steady state method and evaluated dimensionless figure merit at room temperature. The values of Seebeck coefficient, the electrical resistivity, thermal conductivity and dimensionless figure merit are about -260 µV/K, 3 mΩcm, 0.5 W/m K and ~ 0.35 respectively at 420 K.


2007 ◽  
Vol 280-283 ◽  
pp. 397-400 ◽  
Author(s):  
Jing Liu ◽  
Jing Feng Li

Bi2Te3-based alloys are currently best-known, technological thermoelectric materials near room temperature. In this paper, Bi2Te3 and nano-SiC dispersed Bi2Te3 were prepared by mechanical alloying followed by spark plasma sintering (SPS). Raw powders of Bi, Te and SiC were mixed and mechanically alloyed in an argon atmosphere using a planetary ball mill. The SPS temperature was 623K, and the holding time was 5 minutes. The samples were characterized by X-ray Diffraction (XRD) and Scanning electron Microscope (SEM). The thermoelectric properties: i.e. Seebeck coefficient, electrical resistivity and thermal conductivity were measured at temperatures from room temperature to 573K, followed by the evaluation of figure of merit. The results revealed that the SiC dispersion in the Bi2Te3 matrix increased Seebeck coefficient. Although the electrical resistivity was increased somewhat, the thermal conductivity was reduced by the SiC dispersion, indicating that promising thermoelectric materials with enhanced mechanical properties may be obtained in the nano-SiC dispersed Bi2Te3 composites with optimal compositions.


2005 ◽  
Vol 886 ◽  
Author(s):  
Atsuko Kosuga ◽  
Ken Kurosaki ◽  
Hiroaki Muta ◽  
Shinsuke Yamanaka

ABSTRACTPolycrystalline-sintered samples of Tl2GeTe3, Tl4SnTe3, and Tl4PbTe3 were prepared by a solid-state reaction. Their thermoelectric properties were evaluated at temperatures ranging from room temperature to ca. 700 K by using the measured electrical resistivity (ρ), Seebeck coefficient (S), and thermal conductivity (κ). Despite their poor electrical properties, the dimensionless figure of merit ZT of all the compounds was relatively high, i.e., 0.74 at 673 K for Tl4SnTe3, 0.71 at 673 K for Tl4PbTe3, 0.29 at 473 K for Tl2GeTe3, due to the very low lattice thermal conductivity of the compounds.


2012 ◽  
Vol 90 (12) ◽  
pp. 1209-1221 ◽  
Author(s):  
A.K. Patidar ◽  
R.K. Pensia ◽  
V. Shrivastava

The problem of radiative instability of homogeneous rotating partially ionized plasma incorporating viscosity, porosity, and electron inertia in the presence of a magnetic field is investigated. A general dispersion relation is obtained using normal mode analysis with the help of relevant linearized perturbation equations of the problem. The modified Jeans criterion of instability is obtained. The conditions of Jeans instabilities are discussed in the different cases of interest. It is found that the simultaneous effect of viscosity, rotation, finite conductivity, and porosity of the medium does not essentially change the Jeans criterion of instability. It is also found that the presence of arbitrary radiative heat-loss function and thermal conductivity modified the conditions of Jeans instability for longitudinal propagation. It is found that, for longitudinal propagation, the conditions of radiative instability are independent of magnetic field, viscosity, rotation, finite electrical resistivity, and electron inertia, but for the transverse mode of propagation it depends upon finite electrical resistivity and strength of magnetic field and is independent of viscosity, electron inertia, and rotation. From the curves we find that viscosity has a stabilizing effect on the growth rate of instability but the thermal conductivity and density-dependent heat-loss function has a destabilizing effect on the instability growth rate.


2000 ◽  
Vol 281-282 ◽  
pp. 926-927 ◽  
Author(s):  
T Akazawa ◽  
H Ikeda ◽  
N Ozawa ◽  
H Kouno ◽  
R Yoshizaki

2021 ◽  
Author(s):  
Elham Sadeghi ◽  
Hamed Rezania

Abstract In this paper, the transport properties of a two-dimensional Lieb lattice that is a line-centered square lattice are investigated in the presence of magnetic field and spin-orbit coupling. Specially, we address the temperature dependence of electrical and thermal conductivities as well as Seebeck coefficient due to spin-orbit interaction. We have exploited Green’s function approach in order to study thermoelectric and transport properties of Lieb lattice in the context of Kane-Mele model Hamiltonian. The results for Seebeck coefficient show the sign of thermopower is positive in the presence of spin-orbit coupling. Also the temperature dependence of transport properties indicates that the increase of spin-orbit coupling leads to decrease thermal conductivity however the decrease of gap 1 parameter causes the reduction of thermal conductivity. There is a peak in temperature dependence of thermal conductivity for all values of magnetic fields and spin-orbit coupling strengths. Both electrical and thermal conductivities increase with increasing the temperature at low amounts of temperature due to the increasing of transition rate of charge carriers and excitation of them to the conduction bands. Also we have studied the temperature dependence of spin susceptibility of Lieb monolayer due to both spin orbit coupling and magnetic field factors in details.


1985 ◽  
Vol 71 (1) ◽  
pp. 243-245 ◽  
Author(s):  
V.S. Zemskov ◽  
A.D. Belaya ◽  
G.N. Kozhemyakin ◽  
V.G. Lyuttsau ◽  
Y.P. Kostyukova

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