Enhanced Thermoelectric Properties of FeSbx Nanocomposites Through Stoichiometric Adjustment

2012 ◽  
Vol 1456 ◽  
Author(s):  
Mani Pokharel ◽  
Huaizhou Zhao ◽  
Kevin Lukas ◽  
Zhifeng Ren ◽  
Cyril Opeil
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Carrier Concentration ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Hall Coefficient

ABSTRACTThe Seebeck coefficient, electrical resistivity, thermal conductivity and Hall coefficient of FeSbx (x = 2.04, 2.00, and 1.96) nanocomposites hot pressed at 300 °C were measured. The power factor of FeSb1.96 was increased by 105% compared to FeSb2. Hall coefficient measurements revealed a decreased carrier concentration and increased mobility in FeSb1.96 with an overall enhancement in ZTof 45% in FeSb1.96 .

scholarly journals Improving the Thermoelectric Properties of the Half-Heusler Compound VCoSb by Vanadium Vacancy

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1637 ◽  
Author(s):  
Lihong Huang ◽  
Junchen Wang ◽  
Xiaobo Mo ◽  
Xiaobo Lei ◽  
Sude Ma ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Seebeck Coefficient ◽  
Carrier Concentration ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Secondary Phase ◽  
Thermoelectric Performance ◽  
Heusler Compound

The effects of V vacancy on the thermoelectric performance of the half-Heusler compound VCoSb have been investigated in this study. A certain amount of CoSb secondary phase is generated in the VCoSb matrix when the content of V vacancy is more than 0.1 at%. According to the results, a ZT value of 0.6, together with a power factor of 29 μW cm−1 K−2 at 873 K, were achieved for the nonstoichiometric sample V0.9CoSb. This proved that moderate V vacancy could improve the thermoelectric (TE) properties of VCoSb. The noticeable improvements are mainly owing to the incremental Seebeck coefficient, which may benefit from the optimized carrier concentration. However, too much V vacancy will result in more CoSb impurity and deteriorate the TE performances of VCoSb owing to the increased thermal conductivity.

Thermoelectric Properties of Zn4-xSb3 with x=0~0.5

2007 ◽  
Vol 124-126 ◽  
pp. 1019-1022 ◽  
Author(s):  
K.W. Jang ◽  
Il Ho Kim ◽  
Jung Il Lee ◽  
Good Sun Choi
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Temperature Dependence ◽  
Carrier Concentration ◽  
Thermoelectric Properties ◽  
Hall Mobility ◽  
Room Temperature ◽  
Vacuum Melting ◽  
Increasing Temperature

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.

FEM Analysis on Thermoelectric Properties of Metal/TiO2–x Composites with Random Distribution of Metal Powder

2013 ◽  
Vol 750 ◽  
pp. 130-133
Author(s):  
Katsuhiro Sagara ◽  
Yun Lu ◽  
Dao Cheng Luan
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Figure Of Merit ◽  
Random Distribution ◽  
The Other ◽  
Dimensionless Figure Of Merit ◽  
Wide Range

Analysis model of finite element method with a random distribution for thermoelectric composites was built. Thermoelectric properties including electrical resistivity, Seebeck coefficient and thermal conductivity of M/TiO2–x (M = Cu, Ni, 304 stainless steel (304SS)) thermoelectric composites were investigated by the proposed model. Cu/TiO2–x composite showed a large decrease in electrical resistivity while 304SS/TiO2–x composite thermal conductivity was slightly increased. Calculated dimensionless figure-of-merit, ZT of Ni/TiO2–x composite was higher than those of TiO2–x and the other composites in a wide range of metal volume fractions because Ni has large absolute values of Seebeck coefficient, power factor and dimensionless figure-of-merit compared to the other two metals. It was found that power factor and dimensionless figure-of-merit of thermoelectric composites depended on the balance among electrical resistivity, thermal conductivity and Seebeck coefficient. The results revealed that it is important for M/TiO2–x composites to choose suitable addition metal with high power factor and dimensionless figure-of-merit.

Thermoelectric Properties of n-type (Bi2Se3)x(Bi2Te3)1-x Crystals Prepared by Zone Melting

2008 ◽  
Vol 368-372 ◽  
pp. 547-549
Author(s):  
Jun Jiang ◽  
Ya Li Li ◽  
Gao Jie Xu ◽  
Ping Cui ◽  
Li Dong Chen
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Carrier Concentration ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Zone Melting ◽  
Chemical Compositions ◽  
Melting Method ◽  
Temperature Range

In the present study, n-type (Bi2Se3)x(Bi2Te3)1-x crystals with various chemical compositions were fabricated by the zone melting method. Thermoelectric properties, including Seebeck coefficient (α), electrical conductivity (σ) and thermal conductivity (κ), were measured in the temperature range of 300-500 K. The influence of the variations of Bi2Te3 and Bi2Se3 content on thermoelectric properties was studied. The increase of Bi2Se3 content (x) caused an increase in carrier concentration and thus an increase of σ and a decrease of α. The maximum figure of merit (ZT = α2σT/κ) of 0.87 was obtained at about 325 K for the composition of 93%Bi2Te3-7%Bi2Se3 with doping TeI4.

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.

High-temperature thermoelectric properties of W-substituted CaMnO3

2013 ◽  
Vol 1490 ◽  
pp. 3-8 ◽  
Author(s):  
Dimas S. Alfaruq ◽  
James Eilertsen ◽  
Philipp Thiel ◽  
Myriam H Aguirre ◽  
Eugenio Otal ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
High Temperature ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Soft Chemistry ◽  
Absolute Seebeck Coefficient

AbstractThe thermoelectric properties of W-substituted CaMn1-xWxO3-δ (x = 0.01, 0.03; 0.05) samples, prepared by soft chemistry, were investigated from 300 K to 1000 K and compared to Nb-substituted CaMn0.98Nb0.02O3-δ. All compositions exhibit both an increase in absolute Seebeck coefficient and electrical resistivity with temperature. Moreover, compared to the Nb-substituted sample, the thermal conductivity of the W-substituted samples was strongly reduced. This reduction is attributed to the nearly two times greater mass of tungsten. Consequently, a ZT of 0.19 was found in CaMn0.97W0.03O3-δ at 1000 K, which was larger than ZT exhibited by the 2% Nb-doped sample.

Thermoelectric Properties of Carbon Nanotubes Added n-type CoSb3 Compound

2011 ◽  
Vol 1314 ◽  
Author(s):  
Takashi Itoh ◽  
Masashi Tachikawa
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Phonon Scattering ◽  
Pulse Discharge ◽  
Molar Ratios ◽  
Performance Reduction ◽  
Compound Matrix

ABSTRACTCobalt triantimonide compounds are well known as materials with good thermoelectric properties over temperature range of 550-900 K. For further improving thermoelectric performance, reduction of thermal conductivity is required. In this study, we attempted to disperse carbon nanotubes (CNTs) homogeneously into the n-type CoSb3 compound for lowering lattice thermal conductivity by the phonon scattering. Powders of Co, Ni, Sb and Te were blended with molar ratios of n-type Co0.92Ni0.08Sb2.96Te0.04 compound, and the compound was synthesized through a pulse discharge sintering (PDS) process. After coarsely grinding the synthesized compound, CNTs were mixed with the compound powder at different mass% (0, 0.01, 0.05 and 0.1 mass%). Then, the mixture was mechanically ground with a planetary ball milling equipment. The ground composite powder was compacted and sintered by PDS. Thermoelectric properties (Seebeck coefficient, electrical resistivity and thermal conductivity) of the sintered samples were measured. It was confirmed that the fibrous CNTs existed homogeneously in the compound matrix. The absolute value of Seebeck coefficient slightly decreased with increase of CNT content. The minimum thermal conductivity was obtained at addition of 0.01mass%CNT, and the electrical resistivity was a little increased with CNT content. The maximum ZT of 0.98 was achieved at 853 K in the 0.01mass%CNT-added sample.

Enhancement of thermoelectric properties by Na doping in Te-free p-type AgSbSe2

2015 ◽  
Vol 44 (3) ◽  
pp. 1046-1051 ◽  
Author(s):  
Songting Cai ◽  
Zihang Liu ◽  
Jianyong Sun ◽  
Rui Li ◽  
Weidong Fei ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Carrier Concentration ◽  
Thermoelectric Properties ◽  
Point Defects ◽  
Power Factor ◽  
Stacking Faults ◽  
Na Doping ◽  
P Type

Na substituting Sb in the AgSbSe2 not only improves the power factor caused by the enhanced carrier concentration, but also decreases the thermal conductivity due to point defects, nanoscale stacking faults and Na-rich precipitate. Consequently, a high ZT value of 0.92 is achieved in the AgSb0.99Na0.01Se2 sample.

Thermoelectric properties of InxPbxCo4Sb12 prepared by HPHT

2016 ◽  
Vol 09 (01) ◽  
pp. 1650008 ◽  
Author(s):  
Le Deng ◽  
Li Bin Wang ◽  
Jie Ming Qin ◽  
Xiao Peng Jia ◽  
Hong An Ma
Keyword(s):  
Thermal Conductivity ◽  
High Pressure ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
Substantial Reduction ◽  
X Ray Diffraction ◽  
X Ray

We prepared InxPbxCo4Sb[Formula: see text] by high-pressure and high-temperature (HPHT) method. Samples were characterized by X-ray diffraction (XRD), electron microprobe analysis and thermoelectric properties measurements. The Seebeck coefficient, electrical resistivity and thermal conductivity of InxPbxCo4Sb[Formula: see text] samples were all performed in the temperature range of 323–723[Formula: see text]K. With the increasing synthetic pressure, the Seebeck coefficient of In[Formula: see text]Pb[Formula: see text]Co4Sb[Formula: see text] samples, which synthesized between 1.5 GPa–2.3 GPa, showed an obvious increase while the thermal conductivity exhibited a substantial reduction.

scholarly journals Thermoelectric Properties of Bi2Te3: CuI and the Effect of Its Doping with Pb Atoms

2017 ◽  
Author(s):  
Mi-Kyung Han ◽  
Yingshi Jin ◽  
Da-Hee Lee ◽  
Sung-Jin Kim
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Transport Properties ◽  
Carrier Concentration ◽  
Thermoelectric Properties ◽  
Thermal Transport ◽  
Co Doping ◽  
Thermal Transport Properties ◽  
Co Doped

In order to understand the effect of Pb-CuI co-doping on the thermoelectric performance of Bi2Te3, n-type Bi2Te3 co-doped with x at% CuI and 1/2x at% Pb (x = 0, 0.01, 0.03, 0.05, 0.07, and 0.10) were prepared via high temperature solid state reaction and consolidated using spark plasma sintering. Electron and thermal transport properties, i.e., electrical conductivity, carrier concentration, Hall mobility, Seebeck coefficient, and thermal conductivity, of CuI-Pb co-doped Bi2Te3 were measured in the temperature range from 300 K to 523 K and compared to corresponding x% of CuI-doped Bi2Te3 and undoped Bi2Te3. The addition of a small amount of Pb significantly decreased the carrier concentration, which could be attributed to the holes from Pb atoms, thus the CuI-Pb co-doped samples show a lower electrical conductivity and a higher Seebeck coefficient compared to CuI-doped samples with similar x values. The incorporation of Pb into CuI-doped Bi2Te3 rarely changed the power factor because of the trade-off relationship between the electrical conductivity and the Seebeck coefficient. The total thermal conductivity(κtot) of co-doped samples (κtot ~1.4 W/m∙K at 300 K) is slightly lower than that of 1% CuI-doped Bi2Te3 (κtot~1.5 W/m∙K at 300 K) and undoped Bi2Te3 (κtot ~1.6 W/m∙K at 300 K) due to the alloy scattering. The 1% CuI-Pb co-doped Bi2Te3 sample shows the highest ZT value of 0.96 at 370 K. All data on electrical and thermal transport properties suggest that the thermoelectric properties of Bi2Te3 and its operating temperature can be controlled by co-doping.

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