scholarly journals Synthesis and Thermoelectric Properties of C60/Cu2GeSe3Composites

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Degang Zhao ◽  
Jiai Ning ◽  
Shuyu Li ◽  
Min Zuo
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Grain Boundaries ◽  
Ball Milling ◽  
Thermoelectric Properties ◽  
Phonon Scattering ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Average Size

Nanosized C60powder was sufficiently incorporated with Cu2GeSe3powder by ball milling and C60/Cu2GeSe3composites were prepared by spark plasma sintering. C60distributed uniformly in the form of clusters and the average size of cluster was lower than 1 μm. With the addition of C60increasing, the electrical resistivity and Seebeck coefficient of C60/Cu2GeSe3composites increased while the thermal conductivity decreased significantly which resulted from the phonon scattering by C60clusters locating on the grain boundaries of Cu2GeSe3matrix. The maximumZTof 0.20 was achieved at 700 K for 0.9% C60/Cu2GeSe3sample.

Synthesis and Thermoelectric Properties of N-Type Bi2Te2.7Se0.3 Compounds by Spark Plasma Sintering

2005 ◽  
Vol 486-487 ◽  
pp. 654-657
Author(s):  
Dong Choul Cho ◽  
Cheol Ho Lim ◽  
Ki Tae Kim ◽  
Seung Y. Shin ◽  
D.M. Lee ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Hydrogen Reduction ◽  
Sintering Temperature ◽  
Reduction Process ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Temperature Time

Thermoelectric properties of the spark plasma sintered n-type Bi2Te2.7Se0.3 compounds were characterized with the sintering temperature, time and hydrogen reduction process. The Seebeck coefficient, electrical resistivity and thermal conductivity were dependent on hydrogen reduction process as well as sintering temperature. The Seebeck coefficient and electrical resistivity decreased and thermal conductivity increased with reduction treatment and sintering temperature. The results suggest that the carrier density varies with the dissolved oxygen and Te vacancies generated during the pulverization process. The highest figure of merit of 3.11×10-3/K was obtained for the compounds spark plasma sintered at 460°C for 16min by using the reduced powders.

scholarly journals Effect of ZnO and SnO2 Nanolayers at Grain Boundaries on Thermoelectric Properties of Polycrystalline Skutterudites

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2270
Author(s):  
Sang-il Kim ◽  
Jiwoo An ◽  
Woo-Jae Lee ◽  
Se Kwon ◽  
Woo Nam ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Atomic Layer Deposition ◽  
Grain Boundaries ◽  
Thermoelectric Properties ◽  
Phonon Scattering ◽  
Atomic Layer ◽  
Deposition Method ◽  
Plasma Sintering ◽  
Layer Deposition ◽  
Atomic Layer Deposition Method

Nanostructuring is considered one of the key approaches to achieve highly efficient thermoelectric alloys by reducing thermal conductivity. In this study, we investigated the effect of oxide (ZnO and SnO2) nanolayers at the grain boundaries of polycrystalline In0.2Yb0.1Co4Sb12 skutterudites on their electrical and thermal transport properties. Skutterudite powders with oxide nanolayers were prepared by atomic layer deposition method, and the number of deposition cycles was varied to control the coating thickness. The coated powders were consolidated by spark plasma sintering. With increasing number of deposition cycle, the electrical conductivity gradually decreased, while the Seebeck coefficient changed insignificantly; this indicates that the carrier mobility decreased due to the oxide nanolayers. In contrast, the lattice thermal conductivity increased with an increase in the number of deposition cycles, demonstrating the reduction in phonon scattering by grain boundaries owing to the oxide nanolayers. Thus, we could easily control the thermoelectric properties of skutterudite materials through adjusting the oxide nanolayer by atomic layer deposition method.

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.

Effect of Oxygen Content on Thermoelectric Properties of Sintered Bi-Te Based Compounds

2004 ◽  
Vol 449-452 ◽  
pp. 905-908 ◽  
Author(s):  
Dong Choul Cho ◽  
Cheol Ho Lim ◽  
D.M. Lee ◽  
Seung Y. Shin ◽  
Chung Hyo Lee
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Oxygen Content ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Air Atmosphere ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Effect Of Oxygen

The n-type thermoelectric materials of Bi2Te2.7Se0.3 doped with SbI3 were prepared by spark plasma sintering technique. The powders were ball-milled in an argon and air atmosphere. Then, powders were reduced in H2 atmosphere. Effects of oxygen content on the thermoelectric properties of Bi2Te2.7Se0.3 compounds have been investigated. Seebeck coefficient, electrical resistivity and thermal conductivity of the sintered compound were measured at room temperature. It was found that the effect of atmosphere during the powder production was remarkable and thermoelectric properties of sintered compound were remarkably improved by H2 reduction of starting powder. The obtained maximum figure of merit was 2.4 x 10-3/K.

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.

Preparation and Thermoelectric Properties of Bi-Doped Mg2Si Nanocomposites

2009 ◽  
Vol 66 ◽  
pp. 17-20 ◽  
Author(s):  
Mei Jun Yang ◽  
Wei Jun Luo ◽  
Qiang Shen ◽  
Hong Yi Jiang ◽  
Lian Meng Zhang
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Dimensionless Figure Of Merit ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Heavy Doping ◽  
Nanocomposite Structures

Nanocomposites and heavy doping both are regarded as effective way to improve materials’ thermoelectric properties. 0.7at% Bi-doped Mg2Si nanocomposites were prepared by spark plasma sintering. Results of thermoelectric properties tests show that the doping of Bi atom effectively improves the electrical conductivity of Mg2Si，and the nanocomposite structures are helpful to reduce thermal conductivity and increase Seebeck coefficient, hence improving the thermoelectric performance. A maximum dimensionless figure of merit of 0.8 is obtained for the Bi-doped Mg2Si nanocomposite with 50 wt % nanopowder inclusions at 823K, about 63% higher than that of Bi-doped Mg2Si sample without nanopowder inclusions and 119% higher than that of microsized Mg2Si sample without Bi-doped, respectively.

THERMOELECTRIC PROPERTIES OF p-TYPE SKUTTERUDITES (Pr0.25Nd0.75)xFe3CoSb12 BY LEVITATION MELTING AND SPARK PLASMA SINTERING

2013 ◽  
Vol 06 (05) ◽  
pp. 1340006 ◽  
Author(s):  
JINGSHU XU ◽  
CHENGUANG FU ◽  
JIAN XIE ◽  
XINBING ZHAO ◽  
TIEJUN ZHU
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Spark Plasma Sintering ◽  
Thermoelectric Properties ◽  
Lattice Thermal Conductivity ◽  
Levitation Melting ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
P Type

The p-type skutterudite compounds of ( Pr 0.25 Nd 0.75)x Fe 3 CoSb 12 (x = 0.67–0.78) have been successfully synthesized by levitation melting followed by annealing and spark plasma sintering. The thermoelectric properties have been characterized by the measurements of Seebeck coefficient, electrical conductivity and thermal conductivity in the temperature range from 300 K to 850 K. The improvement in the thermoelectric properties was realized due to the reduction in the lattice thermal conductivity when the voids were partially filled by Pr 0.25 Nd 0.75. The maximum ZT value of ~ 0.83 for ( Pr 0.25 Nd 0.75)0.76 Fe 3 CoSb 12 was obtained at 700 K.

Phase Purity and Thermoelectric Properties of Type-I Clathrates Ba8CuxSiyGe46-x-y (4 ≤ x ≤ 6.5, y = 0 and 5.15 ≤ x ≤ 6.425, 2.05≤ y ≤ 36.9)

2017 ◽  
Vol 1142 ◽  
pp. 37-44
Author(s):  
Yue Dong ◽  
Xin Lin Yan ◽  
Zhao Hui Tang ◽  
Xue Yong Ding ◽  
Xu Dong Sun ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Ball Milling ◽  
Thermoelectric Properties ◽  
Hot Pressing ◽  
Type I ◽  
Phase Purity ◽  
Arc Melting ◽  
Elemental Substitution ◽  
Plasma Sintering ◽  
Spark Plasma

Type-I clathrates have been considered as very promising thermoelectric (TE) materials thus attracting attention widely. Here we report new clathrates Ba8CuxSiyGe46-x-y (4≤ x ≤ 6.5, y = 0 and 5.15 ≤ x ≤ 6.425, 2.05≤ y ≤ 36.9), focusing on their phase purity and TE properties. Our results show that samples prepared by arc melting followed by annealing are multi-phases alloys. The composition of the clathrate phase is also inhomogeneous. This indicates that the kinetic factor dominates the reaction of forming the clathrate phase during element-melting and sample-annealing. We select three compositions in these two series of samples, which have less impurity and better composition homogeneity for the clathrate phase, and the annealed alloys are furthered processed by ball milling (BM) and powder-solidification (either by hot pressing (HP) or by spark plasma sintering (SPS)) for TE properties investigations. The BM and HP/SPS processes can improve the phase purity and homogeneity. The TE measurements show that the Si-substituted samples have better performance than the Ge-based sample, mainly by decreasing the electrical resistivity. This indicates that the elemental substitution may be still an effective way to improve the TE performance of clathrates.

Thermoelectric Performances of ZrNiSn/C60 Composite

2007 ◽  
Vol 280-283 ◽  
pp. 385-388 ◽  
Author(s):  
Xiang Yang Huang ◽  
Li Dong Chen ◽  
X. Shi ◽  
Min Zhou ◽  
Z. Xu
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Matrix Alloy ◽  
Nano Particles ◽  
Xrd Pattern ◽  
Plasma Sintering ◽  
Epma Analysis ◽  
Spark Plasma

The ZrNiSn/C60 thermoelectric composite was prepared by a spark plasma sintering (SPS)technique. The obtained sample was fully dense and homogeneous. Slices of the sample were characterized by electrical resistivity, Seebeck coefficient and thermal conductivity up to 850K. It was shown that the composite has a higher electrical conductivity, a lower Seebeck coefficient and a higher thermal conductivity than the ZrNiSn matrix alloy. XRD pattern and EPMA analysis of the composite revealed that the C60 nano particles reacted with ZrNiSn matrix to form ZrC inclusions.

Thermoelectric Properties of La-doped BaSi2 and (Ba,Sr)Si2 Solid Solutions

2007 ◽  
Vol 1044 ◽  
Author(s):  
Kohsuke Hashimoto ◽  
Ken Kurosaki ◽  
Hiroaki Muta ◽  
Shinsuke Yamanaka
Keyword(s):  
Thermal Conductivity ◽  
Solid Solution ◽  
Electrical Resistivity ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Dimensionless Figure Of Merit ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
La Doped

AbstractWe studied the thermoelectric properties of BaSi2 and SrSi2. The polycrystalline samples were prepared by spark plasma sintering (SPS). The electrical resistivity (ρ), Seebeck coefficient (S), and thermal conductivity (κ) were measured above room temperature. The maximum values of the dimensionless figure of merit (ZT) were 0.01 at 954 K for BaSi2 and 0.09 at 417 K for SrSi2. We tried to enhance the ZT values of BaSi2 and SrSi2 by prepareing and characterizing La-doped BaSi2 and (Ba,Sr)Si2 solid solution.

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