scholarly journals Solid-State Synthesis and Thermoelectric Properties of Mg2+xSi0.7Sn0.3Sbm

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Sin-Wook You ◽  
Il-Ho Kim ◽  
Soon-Mok Choi ◽  
Won-Seon Seo
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Solid State ◽  
Seebeck Coefficient ◽  
Solid Solutions ◽  
Solid State Synthesis ◽  
Sb Doping ◽  
Excess Mg ◽  
Bipolar Conduction ◽  
Type Conduction

Mg2+xSi0.7Sn0.3Sbm(0≤x≤0.2,m=0or 0.01) solid solutions have been successfully prepared by mechanical alloying and hot pressing as a solid-state synthesis route. All specimens were identified as phases with antifluorite structure and showed n-type conduction. The electrical conductivity of Mg-excess solid solutions was enhanced due to increased electron concentrations. The absolute values of the Seebeck coefficient varied substantially with Sb doping and excess Mg, which was attributed to the change in carrier concentration. The onset temperature of bipolar conduction was shifted higher with Sb doping and excess Mg. The lowest thermal conductivity of 1.3 W/mK was obtained for Mg2Si0.7Sn0.3Sb0.01. A maximumZTof 0.64 was achieved at 723 K for Mg2.2Si0.7Sn0.3Sb0.01.

Thermoelectric Properties of Ag1-xPbmSbTe2+m Compounds

2007 ◽  
Vol 336-338 ◽  
pp. 854-856
Author(s):  
Yong Gao Yan ◽  
Xin Feng Tang ◽  
Hai Jun Liu ◽  
Ling Ling Yin ◽  
Qing Jie Zhang
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Spark Plasma Sintering ◽  
Thermoelectric Properties ◽  
M 10 ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Type Conduction

Ag1-xPbmSbTe2+m (m = 6, 10, 18; x = 0, 0.5, 0.75) compounds were prepared by melting-spark plasma sintering (SPS) process. The effects of m and x on the thermoelectric properties of the compounds were investigated. The results indicate that all samples are n-type conduction. For Ag1-xPb18SbTe20 (x = 0, 0.5, 0.75), the electrical conductivity decreases, whereas Seebeck coefficient increases, with increasing Ag concentration. For AgPbmSbTe2+m (m = 6, 10, 18), as m increases, the Seebeck coefficient slightly decreases and the electrical conductivity increases first, with a maximum at m =10, and then decreases. The thermal conductivity increases with increasing m.

High Temperature Thermoelectric Property of Sr-Filled Skutterudite SryCo4Sb12

2007 ◽  
Vol 336-338 ◽  
pp. 842-845
Author(s):  
Xue Ying Zhao ◽  
Xun Shi ◽  
Li Dong Chen ◽  
Sheng Qiang Bai ◽  
Wen Bing Zhang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Chemical Composition ◽  
Seebeck Coefficient ◽  
Figure Of Merit ◽  
Thermoelectric Figure ◽  
Filled Skutterudite ◽  
Absolute Value ◽  
Homogeneous Chemical ◽  
Type Conduction

Sr-filled skutterudite compounds SryCo4Sb12 (y=0-0.20) were synthesized by melting method. XRD and EPMA results revealed that the obtained samples are single skutterudite phase with homogeneous chemical composition. The lattice parameters increase linearly with increasing Sr content in the range of y=0-0.20. The thermal conductivity, electrical conductivity and Seebeck coefficient were measured in the temperature range of 300-850K. The measurement of Hall effect was performed by Van de Pauw method at room temperature. The obtained Sr-filled skutterudite exhibits n-type conduction. The absolute value of the Seebeck coefficient of SryCo4Sb12 decreases with the increase of Sr content. The electrical conductivity increases with the increase of Sr content. The lattice thermal conductivity of SryCo4Sb12 is significantly depressed as compared with unfilled CoSb3. The maximum dimensionless thermoelectric figure of merit is 0.7 for Sr0.20Co4Sb12 at 850K. Further optimization of chemical composition would improve the thermoelectric performance.

Development of Al2O3-ZnO/Ca3Co4O9 Module for Thermoelectric Power Generation

2009 ◽  
Vol 1166 ◽  
Author(s):  
Paolo Mele ◽  
Kaname Matsumoto ◽  
Takeshi Azuma ◽  
Keita Kamesawa ◽  
Saburo Tanaka ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Power Generation ◽  
Electrical Conductivity ◽  
Solid State ◽  
Seebeck Coefficient ◽  
Thermoelectric Power ◽  
Output Power ◽  
Thermoelectric Power Generation ◽  
Diamond Saw ◽  
Conventional Solid State Synthesis

AbstractPure and Al2O3(2%, 5%, 8%) doped sintered ZnO (n-type) and pure sintered Ca3Co4O9 (p-type) pellets were prepared by conventional solid state synthesis starting from the oxides. The sintered pellets were cut by a diamond saw in a pillar shape (15 mm×5 mm×5 mm) for experimental checks. The best doped sample was 2 % Al2O3 ZnO showing Seebeck coefficient S = -180 mV/K and electrical conductivity σ = 8 S/cm at 400°C, while thermal conductivity κ = 1.8 W/m×K at 600°C. Typical values for Ca3Co4O9 were S = 82.5 mV/K and σ = 125 S/cm at 800°C, while κ = 1.01 W/m×K at 600°C. Several modules fabricated by elements cut from sintered pellets were tested and the best performance was obtained in the module formed by six 2 % Al2O3ZnO/ Ca3Co4O9 couples, that generated an output power P = 300 mV at 500°C (when ΔT = 260°C).

Electrical and thermal transport properties of the Y1 − x Mx CrO3 system

1986 ◽  
Vol 1 (5) ◽  
pp. 675-684 ◽  
Author(s):  
W.J. Weber ◽  
C.W. Griffin ◽  
J.L. Bates
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Dopant Concentration ◽  
Strong Dependence ◽  
Divalent Metal Ions ◽  
Ionic Radii ◽  
Measured Activation ◽  
Small Polarons ◽  
Type Conduction

The effects of substituting divalent metal ions (Mg, Ca, Sr, Ba) for Y in YCrO3 were investigated by electrical conductivity, Seebeck coefficient, and thermal conductivity measurements. The electrical conductivity results were consistent with the hopping-type conduction of a temperature-independent concentration of small polarons, with measured activation energies of 0.18-0.26 eV. The Seebeck coefficient increased nearly linearly with temperature and indicated p-type conductivity. Both electrical conductivity and Seebeck coefficient results show a strong dependence on dopant size (ionic radius) and indicate that the highest carrier concentrations were associated with Ca as the dopant, which is attributed to the similar ionic radii of Ca2+ and Y3+. The thermal conductivity decreased slightly with temperature and dopant concentration.

scholarly journals Морфология и термоэлектрические свойства керамики твердых растворов γ-Gd-=SUB=-x-=/SUB=-Dy-=SUB=-1-x-=/SUB=-S-=SUB=-1.5-y-=/SUB=-

2020 ◽  
Vol 62 (4) ◽  
pp. 537
Author(s):  
А.В. Сотников ◽  
В.В. Баковец ◽  
Michihiro Ohta ◽  
А.Ш. Агажанов ◽  
С.В. Станкус
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Specific Surface ◽  
Solid Solutions ◽  
Figure Of Merit ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
Temperature Dependences

The temperature dependences of Seebeck coefficient, electrical conductivity (Т=300–873K), thermal conductivity and figure of merit (Т=300–770K) of polycrystalline samples of solid solutions based on gadolinium and dysprosium sulfides with γ-GdxDy1-xS1.49 (x=0.1, 0.2, 0.3, 0.4) composition were studied. It was established that samples morphological features, namely, the specific surface area of crystallites causing a change in the number of deformation centers determines the thermal conductivity of -GdxDy1-xS1.49, and it was found that there is an anomalous decrease in thermal conductivity for composition with х = 0.2. For this composition the lowest values of Seebeck coefficient -371 mkV/K at 873K, electrical resistivity 880 mkΩ∙m at 873K and thermal conductivity 0.68 ± 0.03 W/m·K at 770K were obtained, in this case the thermoelectric figure of merit reaches ZT = 0.23.

Investigation of Thermoelectric Materials: Substitution effect of Bi on the Ag1-xPb18MTe20 (M = Sb, Bi) (x = 0, 0.14, 0.3)

2007 ◽  
Vol 1044 ◽  
Author(s):  
Mi-kyung Han ◽  
Huijun Kong ◽  
Ctirad Uher ◽  
Mercouri G Kanatzidis
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Materials ◽  
Figure Of Merit ◽  
Lattice Thermal Conductivity ◽  
Substitution Effect ◽  
Dimensionless Figure Of Merit ◽  
The Matrix ◽  
Mass Fluctuation

AbstractWe performed comparative investigations of the Ag1-xPb18MTe20 (M = Bi, Sb) (x = 0, 0.14, 0.3) system to better understand the roles of Sb and Bi on the thermoelectric properties. In both systems, the electrical conductivity nearly keeps the same values, while the Seebeck coefficient decreases dramatically in going from Sb to Bi. Compared to the lattice thermal conductivity of PbTe, that of AgPb18BiTe20 is substantially reduced. The lattice thermal conductivity of the Bi analog, however, is higher than that of AgPb18SbTe20 and this is attributed largely to the decrease in the degree of mass fluctuation between the nanostructures and the matrix (for the Bi analog). As a result the dimensionless figure of merit ZT of Ag1-xPb18MTe20 (M = Bi) is found to be smaller than that of Ag1-xPb18MTe20 (M = Sb).

Fluoride solid electrolytes: investigation of the tysonite-type solid solutions La1−xBaxF3−x (x < 0.15)

2015 ◽  
Vol 44 (45) ◽  
pp. 19625-19635 ◽  
Author(s):  
Johann Chable ◽  
Belto Dieudonné ◽  
Monique Body ◽  
Christophe Legein ◽  
Marie-Pierre Crosnier-Lopez ◽  
...  
Keyword(s):  
Solid State ◽  
Solid Solutions ◽  
Solid Electrolytes ◽  
Nitrogen Atmosphere ◽  
Solid State Synthesis ◽  
Subsequent Quenching

La1−xBaxF3−x solid solutions for x < 0.15 were prepared by solid state synthesis in a platinum tube under an nitrogen atmosphere with subsequent quenching for 0.07 ≤ x < 0.15.

Band Structure and Thermoelectric Properties of Ni(x)Zn(1-x)Fe2O4

2021 ◽  
Vol 317 ◽  
pp. 28-34
Author(s):  
Joon Hoong Lim
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Band Structure ◽  
Seebeck Coefficient ◽  
Band Gap ◽  
Thermoelectric Properties ◽  
Xrd Analysis ◽  
Valence Band Maximum ◽  
Solid State Method ◽  
Ni Content

Thermoelectric materials has made a great potential in sustainable energy industries, which enable the energy conversion from heat to electricity. The band structure and thermoelectric properties of Ni(x)Zn(1-x)Fe2O4 have been investigated. The bulk pellets were prepared from analytical grade ZnO, NiO and Fe2O3 powder using solid-state method. It was possible to obtain high thermoelectric properties of Ni(x)Zn(1-x)Fe2O4 by controlling the ratios of dopants and the sintering temperature. XRD analysis showed that the fabricated samples have a single phase formation of cubic spinel structure. The thermoelectric properties of Ni(x)Zn(1-x)Fe2O4 pellets improved with increasing Ni. The electrical conductivity of Ni(x)Zn(1-x)Fe2O4 pellets decreased with increasing Ni content. The electrical conductivity of Ni(x)Zn(1-x)Fe2O4 (x = 0.0) is (0.515 x10-3 Scm-1). The band structure shows that ZnxCu1-xFe2O4 is an indirect band gap material with the valence band maximum (VBM) at M and conduction band minimum (CBM) at A. The band gap of Ni(x)Zn(1-x)Fe2O4 increased with increasing Ni content. The increasing band gap correlated with the lower electrical conductivity. The thermal conductivity of Ni(x)Zn(1-x)Fe2O4 pellets decreased with increasing Ni content. The presence of Ni served to decrease thermal conductivity by 8 Wm-1K-1 over pure samples. The magnitude of the Seebeck coefficient for Ni(x)Zn(1-x)Fe2O4 pellets increased with increasing amounts of Ni. The figure of merit for Ni(x)Zn(1-x)Fe2O4 pellets and thin films was improved by increasing Ni due to its high Seebeck coefficient and low thermal conductivity.

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.

scholarly journals Термоэлектрические свойства твердых растворов (CuInSe-=SUB=-2-=/SUB=-)-=SUB=-1-x-=/SUB=-(In-=SUB=-2-=/SUB=-Te-=SUB=-3-=/SUB=-)-=SUB=-x-=/SUB=-

2022 ◽  
Vol 56 (1) ◽  
pp. 38
Author(s):  
Ч.И. Абилов ◽  
М.Ш. Гасанова ◽  
Н.Т. Гусейнова ◽  
Э.К. Касумова
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Solid Solutions ◽  
Figure Of Merit ◽  
Charge Carriers ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
Mobility Of Charge Carriers ◽  
Temperature Dependences ◽  
Thermoelectric Coefficient

The results of studying the temperature dependences of electrical conductivity, thermoelectric coefficient, Hall mobility of charge carriers, total and electronic thermal conductivity, as well as phonon thermal resistance of alloys of (CuInSe2)1-x(In2Te3)x solid solutions at x=0.005 and 0.0075 are presented. The values ​​of these parameters for certain temperatures were used to calculate the values ​​of the thermoelectric figure of merit of the indicated compositions. It turned out that as the temperature rises, the thermoelectric figure of merit tends to grow strongly, from which it can be concluded that these materials can be used in the manufacture of thermoelements.

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