LSCO Ceramics as Possible Thermoelectric Material for Low Temperature Applications

2007 ◽  
Vol 1044 ◽  
Author(s):  
Julio E. Rodríguez
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Low Temperature ◽  
Seebeck Coefficient ◽  
Annealing Time ◽  
Oxygen Stoichiometry ◽  
Measured Temperature ◽  
Total Thermal Conductivity ◽  
Metallic Behavior ◽  
Temperature Range

AbstractSeebeck coefficient S(T), thermal conductivity κ(T) and electrical resistivity ρ(T) measurements on polycrystalline La1.85Sr0.15CuO4-δ(LSCO) compounds grown by solid-state reaction method were carried out in the temperature range between 100 and 290K. The obtained samples were submitted to annealing processes of different duration in order to modify their oxygen stoichiometry. The Seebeck coefficient is positive over the measured temperature range and its magnitude increases with the annealing time up to reach values close to 150 µV/K. The electrical resistivity exhibits a metallic behavior, in all samples, ρ(T) takes values less than 1mΩ-cm. As the annealing time increases, the total thermal conductivity increases up to values close to 3 W/K-m. From S(T), κ(T) and ρ(T) data, the thermoelectric power factor (PF) and the dimensionless figure of merit (ZT) were determined. These parameters reach maximum values around 25 µW/K2-cm and 0.18, respectively. The observed behavior in the transport properties become these compounds potential thermoelectric materials, which could be used in low temperature thermoelectric applications.

Thermoelectric Properties of Doped Iron Disilicide

2000 ◽  
Vol 626 ◽  
Author(s):  
Jun-ichi Tani ◽  
Hiroyasu Kido
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Measured Temperature ◽  
Iron Disilicide ◽  
Measured Temperature Range ◽  
Temperature Range

ABSTRACTIn order to investigate the thermoelectric properties of Re-doped β-FeSi2 (Fe1-xRexSi2), Ir-doped β-FeSi2 (Fe1-xIrxSi2), and Pt-doped β-FeSi2 (Fe1-xPtxSi2), the electrical resistivity, the Seebeck coefficient, and the thermal conductivity of these samples have been measured in the temperature range between 300 and 1150 K. Fe1-xRexSi2 is p-type, while Fe1-xIrxSi2 and Fe1-xPt xSi2 are n-type over the measured temperature range. The solubility limits of dopant are estimated to be 0.2at% for Fe1-xRexSi2, 0.5at% for Fe1-xIrxSi2, and 1.9at% for Fe1-xPtxSi2. A maximum ZT value of 0.14 was obtained for Fe1-xPt xSi2 (x=0.03) at the temperature 847 K.

THE LOW-TEMPERATURE THERMAL CONDUCTIVITY, ELECTRICAL RESISTIVITY, AND THERMOELECTRIC POWER OF DILUTE SILVER ALLOYS WITH MANGANESE

1966 ◽  
Vol 44 (10) ◽  
pp. 2293-2302 ◽  
Author(s):  
H. L. Malm ◽  
S. B. Woods
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Low Temperature ◽  
Thermoelectric Power ◽  
Electron Scattering ◽  
The Other ◽  
Temperature Measurements ◽  
Silver Alloys ◽  
Temperature Range ◽  
Dilute Alloy

Low-temperature measurements of electrical resistivity, thermal conductivity, and thermoelectric power on silver alloys containing 0.005, 0.067, 0.11, and 0.31 at.% of manganese are reported. The same specimens were used for the measurement of all properties over the temperature range from 2 to 25 °K. The well-known minimum and maximum are observed in the electrical resistivity of the three more concentrated alloys and the minimum is visible in the most dilute alloy near the lowest temperatures of measurement. Associated effects are observed in the other properties and their possible relationship to theoretical electron scattering mechanisms, particularly that of Kondo, is discussed.

Physical Properties of Ni3Al Containing 24 and 25 Atomic Percent Aluminum

1984 ◽  
Vol 39 ◽  
Author(s):  
R. K. Williams ◽  
R. S. Graves ◽  
F. J. Weaver ◽  
D. L. McElroy
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Thermal Expansion ◽  
Seebeck Coefficient ◽  
Physical Properties ◽  
Atomic Percent ◽  
Thermal Expansion Data ◽  
Ferromagnetic Order ◽  
Temperature Range ◽  
Expansion Coefficients

ABSTRACTThermal conductivity, electrical resistivity, Seebeck coefficient and thermal expansion data were obtained on well-annealed Ni3Al containing 24 and 25 at. % Al. The results span the temperature range 300 to 1000 K. The expansion coefficients did not vary with composition and increased with temperature, reaching values of aIout 17 × 10−6 K−1 at 1000 K. The thermal conductivity and electrical resistivity changed rapidly with composition, and the thermal conductivity of 24 at. % Al is as much as 30% lower than that for stoichiometric Ni3A1. The electronic Lorenz function of Ni3Al was obtained by subtracting the estimated phonon conductivity component and found to be within about 5% of the Sommerfeld prediction from 300 to 1000 K. The electrical resistivity results for stoichiometric Ni 3Al are influenced by the loss of ferromagnetic order at lower temperatures and are not adequately described by the Bloch-Grüneisen equation.

Thermoelectric Properties of NaZn13-type Intermetallic Compounds

2003 ◽  
Vol 793 ◽  
Author(s):  
Y. Amagai ◽  
A. Yamamoto ◽  
C. H. Lee ◽  
H. Takazawa ◽  
T. Noguchi ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Seebeck Coefficient ◽  
Power Factor ◽  
Room Temperature ◽  
Total Thermal Conductivity ◽  
Electrical Measurements ◽  
Metallic Behavior ◽  
Large Power ◽  
Absolute Value ◽  
The Absolute

ABSTRACTWe report the electrical resistivity and the Seebeck coefficient of AZn13(A = Sr, Ba, and La) and LaCo13measured over a wide temperature range and their thermal conductivity measured at room temperature. The electrical measurements of AZn13and LaCo13above room temperature reveal that the compounds show good metallic behavior. We find that the absolute value of Seebeck coefficient for AZn13(A = Sr, Ba, and La) increases with increasing temperature, which is a typical metallic behavior and the absolute value is less than 3μVK−1at room temperature. Accordingly, the power factor of AZn13is quite low. Temperature dependence of the Seebeck coefficient for LaCo13is similar to that of Co. The absolute value of the Seebeck coefficient for LaCo13is high as a metallic conductor and approaches -30μVK−1at 500K, which leads LaCo13to large power factor of 1.8 × 10−3Wm−1K−2. We obtained lattice components of the thermal conductivity by subtracting electronic contributions from the total thermal conductivity. The electronic components of the thermal conductivity were estimated using Wiedemann-Frantz law assumingL(Lorentz number) is 2.45 × 10−8V2K−2. The thermal conductivities of the lattice components for AZn13(A = Sr, Ba, and La) and LaCo13with NaZn13type structure are about 10 Wm−1K−1, respectively. These values are high as compared with other thermoelectric materials.

Thermoelectric behaviour of p- and n- type Ti-Ni-Sn half Heusler alloy variants and their amorphous equivalents

2013 ◽  
Vol 1490 ◽  
pp. 33-40
Author(s):  
Song Zhu ◽  
Satish Vitta ◽  
Terry M. Tritt
Keyword(s):  
Thermal Conductivity ◽  
Seebeck Coefficient ◽  
Heusler Alloys ◽  
Strong Temperature Dependence ◽  
Total Thermal Conductivity ◽  
Temperature Range ◽  
Transport Behaviour ◽  
Increasing Temperature ◽  
P Type ◽  
Amorphous Phase Formation

ABSTRACTTi-Ni-Sn type half-Heusler alloys which have the versatility to be either p- or n-type depending on the type of substitution, have been synthesized and investigated in the present work. The added advantage of doping them with multiple elements is that they will be amenable to bulk amorphous phase formation. The hole doped alloys were predominantly single phase with a cubic structure, while the electron doped alloys were found to have minor additional phases. All the alloys exhibit extremely weak metallic-like or degenerate semiconductor transport behaviour in the temperature range 20 K to 1000 K. The resistivity of p-type alloys exhibits semi-metallic-to-semiconducting transition at ∼ 500 K while the n-type alloys exhibit a weak metallic-like behaviour in the complete temperature range. The Seebeck coefficient has strong temperature dependence with a maximum of 45 μV K−1 in the temperature range 600-700 K in the p-type alloys. The n-type alloys however exhibit a linear variation of the Seebeck coefficient with temperature. The total thermal conductivity of the alloys increases with increasing temperature without any peak at low temperatures indicating significant disorder induced scattering. The p-type alloys have the lowest thermal conductivity compared to the n-type alloys. These alloys become amorphous after pulsed laser deposition except one alloy which exhibits compensated transport behaviour.

Physical Property Evaluation for High Purity Niobium and Tantalum Rare Metals

2007 ◽  
Vol 26-28 ◽  
pp. 1059-1062 ◽  
Author(s):  
Il Ho Kim ◽  
Jung Il Lee ◽  
G.S. Choi ◽  
J.S. Kim
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Low Temperature ◽  
Temperature Dependence ◽  
High Purity ◽  
Phonon Scattering ◽  
Physical Property ◽  
Rare Metals ◽  
Metallic Behavior ◽  
Property Evaluation

Thermal, electrical and mechanical properties of high purity niobium and tantalum refractory rare metals were investigated to evaluate the physical purity. Higher purity niobium and tantalum metals showed lower hardness due to smaller solution hardening effect. Temperature dependence of electrical resistivity showed a typical metallic behavior. Remarkable decrease in electrical resistivity was observed for a high purity specimen at low temperature. However, thermal conductivity increased for a high purity specimen, and abrupt increase in thermal conductivity was observed at very low temperature, indicating typical temperature dependence of thermal conductivity for high purity metals. It can be known that reduction of electron-phonon scattering leads to increase in thermal conductivity of high purity niobium and tantalum metals at low temperature.

scholarly journals Влияние температуры спекания на термоэлектрические свойства соединения Bi-=SUB=-1.9-=/SUB=-Gd-=SUB=-0.1-=/SUB=-Te-=SUB=-3-=/SUB=-

2019 ◽  
Vol 53 (5) ◽  
pp. 620
Author(s):  
М.Н. Япрынцев ◽  
А.Е. Васильев ◽  
О.Н. Иванов
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Elemental Composition ◽  
Figure Of Merit ◽  
Sintering Temperature ◽  
Thermoelectric Figure Of Merit ◽  
Total Thermal Conductivity ◽  
Thermoelectric Figure ◽  
Antisite Defects

AbstractThe regularities of the influence of the sintering temperature (750, 780, 810, and 840 K) on the elemental composition, crystal-lattice parameters, electrical resistivity, Seebeck coefficient, total thermal conductivity, and thermoelectric figure of merit of the Bi_1.9Gd_0.1Te_3 compound are investigated. It is established that the elemental composition of the samples during high-temperature sintering varies due to intense tellurium evaporation, which can lead to the formation of various point defects (vacancies and antisite defects) affecting the majority carrier (electron) concentration and mobility. The sintering temperature greatly affects the electrical resistivity of the samples, while the influence on the Seebeck coefficient and total thermal conductivity is much weaker. The largest thermoelectric figure of merit ( ZT ≈ 0.55) is observed for the sample sintered at 750 K.

Effects of Nb doping on thermoelectric properties of Zn4Sb3 at high temperatures

2009 ◽  
Vol 24 (2) ◽  
pp. 430-435 ◽  
Author(s):  
D. Li ◽  
H.H. Hng ◽  
J. Ma ◽  
X.Y. Qin
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
High Temperatures ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Thermoelectric Performance ◽  
Temperature Range ◽  
A Value ◽  
Nb Doping ◽  
Thermal Conductivities

The thermoelectric properties of Nb-doped Zn4Sb3 compounds, (Zn1–xNbx)4Sb3 (x = 0, 0.005, and 0.01), were investigated at temperatures ranging from 300 to 685 K. The results showed that by substituting Zn with Nb, the thermal conductivities of all the Nb-doped compounds were lower than that of the pristine β-Zn4Sb3. Among the compounds studied, the lightly substituted (Zn0.995Nb0.005)4Sb3 compound exhibited the best thermoelectric performance due to the improvement in both its electrical resistivity and thermal conductivity. Its figure of merit, ZT, was greater than the undoped Zn4Sb3 compound for the temperature range investigated. In particular, the ZT of (Zn0.995Nb0.005)4Sb3 reached a value of 1.1 at 680 K, which was 69% greater than that of the undoped Zn4Sb3 obtained in this study.

Thermoelectric Properties of Semiconducting Intermetallic Compounds: FeGa3and RuGa3

2003 ◽  
Vol 793 ◽  
Author(s):  
Y. Amagai ◽  
A. Yamamoto ◽  
C. H. Lee ◽  
H. Takazawa ◽  
T. Noguchi ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
High Temperature ◽  
Seebeck Coefficient ◽  
Transport Properties ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
High Seebeck Coefficient

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.

scholarly journals Effect of band structure adjustment based of Cu site on the thermoelectric properties of BiCuSeO

2021 ◽  
Author(s):  
Bo Feng
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Effective Mass ◽  
Valence Band ◽  
Thermoelectric Properties ◽  
Density Of States ◽  
First Principles Calculation ◽  
Temperature Range ◽  
Ti Doping

Abstract The effect of Ti doped at Cu site on the thermoelectric properties of BiCuSeO was studied by experimental method and first principles calculation. The results show that Ti doping can cause the lattice contraction and decrease the lattice constant. Ti doping can increase the band gap and lengthen the Cu/Ti-Se bond, resulting in the decrease of carrier concentration. Ti doping can reduce the effective mass and the Bi-Se bond length, correspondingly improve the carrier mobility. Ti doping can decrease the density of states of Cu-3d and Se-4p orbitals at the top of valence band, but Ti-4p orbitals can obviously increase the density of states at the top of valence band and finally increase the electrical conductivity in the whole temperature range. With the decrease of effective mass, Ti doping would reduce the Seebeck coefficient, but the gain effect caused by the increase of electrical conductivity is more than the benefit reduction effect caused by the decrease of Seebeck coefficient, and the power factor shows an upward trend. Ti doping can reduce Young's modulus, lead to the increase of defect scattering and strain field, correspondingly reduce the lattice thermal conductivity and total thermal conductivity. It is greatly increased for the ZT values in the middle and high temperature range, with the highest value of 1.04 at 873 K.

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