Thermoelectric properties of synthesized Mg2Si0.95-xGe0.05Sbx by spark plasma sintering

2015 ◽  
Vol 1735 ◽  
Author(s):  
Asumi Sasaki ◽  
Koya Arai ◽  
Yuto Kimori ◽  
Tomoyuki Nakamura ◽  
Kenjiro Fujimoto ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Carrier Concentration ◽  
Spark Plasma Sintering ◽  
Phonon Scattering ◽  
Laser Flash ◽  
Magnesium Silicide ◽  
X Ray ◽  
Plasma Sintering ◽  
Spark Plasma

AbstractMagnesium silicide (Mg2Si) has attracted much interest as an n-type thermoelectric material because it is eco-friendly, non-toxic, light, and relatively abundant compared with other thermoelectric materials. In this study, we tried to improve the thermoelectric performance by doping Sb and Ge in the Mg2Si, as well as further optimizing x in the carrier concentration to cause phonon scattering. A high purity Mg2Si was synthesized from metal Mg and Sb doped Si-Ge alloy by using spark plasma sintering (SPS) equipment. The sintered samples were cut and polished. They were evaluated by using X-ray diffraction (XRD) and X-ray fluorescence (XRF) analyses. The carrier concentration of the samples was measured by using Hall measurement equipment. The electrical conductivity and Seebeck coefficient were measured by using a standard four-probe method in a He atmosphere. The thermal conductivity was measured by using a laser-flash system. We succeeded in obtaining a Sb doped Mg2Si0.95Ge0.05 sintered body easily without any impurities with the SPS equipment. The electrical conductivity of the sample was increased, and thermal conductivity was decreased by increasing the amount of doped Sb. The dimensionless figure of merit ZT became 0.74 at 733 K in the Mg2Si0.95-xGe0.05Sbx sample with x = 0.0022.

Thermoelectric Properties of Mg2Si1-x-yGexSbyPrepared by Spark Plasma Sintering

MRS Advances ◽  
2016 ◽  
Vol 1 (60) ◽  
pp. 3971-3976 ◽  
Author(s):  
Miharu Iida ◽  
Tomoyuki Nakamura ◽  
Kenjiro Fujimoto ◽  
Yuki Yamaguchi ◽  
Ryuji Tamura ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Carrier Concentration ◽  
Spark Plasma Sintering ◽  
Phonon Scattering ◽  
Raw Material ◽  
Arc Melting ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Magnesium Compound ◽  
Te Material

ABSTRACTThe magnesium compound Mg2Si and its solid solutions are expected asn-type thermoelectric (TE) material because they are non-toxic, have a large Clarke number, and are light weight. In this study, we improved TE performance by doping Ge into Sb-doped Mg2Si to cause phonon scattering and increase carrier concentration. A bulk of Sb-doped Si-Ge alloy as the raw material was fabricated using an arc-melting method. A high-purity Mg2Si was synthesized from metal Mg and Sb-doped Si-Ge alloy using spark plasma sintering equipment. For the samples with the same Sb concentration, the electrical conductivity was equivalent. On the other hand, the Seebeck coefficient was dependent on Ge concentration. Due to phonon scattering, thermal conductivity decreased by a small amount of Ge doping andκphdominated for thermal conduction. The minimum thermal conductivity of Mg2Si0.90Ge0.10was 2.25 W/mK (κph: 2.06 W/mK,κel: 0.19 W/mK). The dimensionless figure of merit (ZT) for the Mg2Si0.945Ge0.05Sb0.005sample was higher than that of the others due to reducing thermal conductivity and increasing carrier concentration. The maximumZTwas 0.47 at 713 K.

Solid-State Synthesis of Magnesium Silicide via Repeated Plastic Working and Spark Plasma Sintering

2005 ◽  
Vol 475-479 ◽  
pp. 2895-2898
Author(s):  
Hideki Oginuma ◽  
Katsuyoshi Kondoh ◽  
Takashi Yamaguchi ◽  
Eiji Yuasa
Keyword(s):  
Solid State ◽  
Spark Plasma Sintering ◽  
Bulk Material ◽  
Magnesium Silicide ◽  
X Ray Diffraction ◽  
Plastic Working ◽  
X Ray ◽  
Plasma Sintering ◽  
Elemental Powder Mixture ◽  
Spark Plasma

In this study, the solid-state reaction to form Mg2Si bulky materials via spark plasma sintering (SPS) process was discussed. Elemental powder mixture of Mg-33.33mol%Si was refined and consolidated as green compacts by repeated plastic working (RPW) SPS was performed to synthesize and sinter magnesium silicide at 1100K from the RPWed compact. The only peaks of Mg2Si, not Mg and Si, were detected by X-ray diffraction analysis. Mg2Si bulky intermetallic began to shrink above 800K during SPS process, and its densification significantly occurred. The density of SPSed Mg2Si bulk material is about 100% of the theoretically relative one.

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.

Thermoelectrical properties of α phase and γ phase NaxCo2O4 ceramics prepared by spark plasma sintering method

2013 ◽  
Vol 1490 ◽  
pp. 57-62 ◽  
Author(s):  
Natsuko Mikami ◽  
Keishi Nishio ◽  
Koya Arai ◽  
Tatsuya Sakamoto ◽  
Masahiro Minowa ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Spark Plasma Sintering ◽  
Figure Of Merit ◽  
Dimensionless Figure Of Merit ◽  
Α Phase ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Sintering Method ◽  
Acid Compound

ABSTRACTThe thermoelectrical properties of α and γ phases of NaxCo2O4 having different amounts of Na were evaluated. The γ NaxCo2O4 samples were synthesized by thermal decomposition in a metal-citric acid compound, and the α NaxCo2O4 samples were synthesized by self-flux processing. Dense bulk ceramics were fabricated using spark plasma sintering (SPS), and the sintered samples were of high density and highly oriented. The thermoelectrical properties showed that γ NaxCo2O4 had higher electrical conductivity and lower thermal conductivity compared with α NaxCo2O4 and that α NaxCo2O4 had a larger Seebeck coefficient. These results show that γ NaxCo2O4 has a larger power factor and dimensionless figure of merit, ZT, than α NaxCo2O4.

Tunable thermopower and thermal conductivity in Lu doped In2O3

RSC Advances ◽  
2014 ◽  
Vol 4 (60) ◽  
pp. 31926-31931 ◽  
Author(s):  
BeiBei Zhu ◽  
Ruoming Tian ◽  
Tianshu Zhang ◽  
Richard Donelson ◽  
Thiam Teck Tan ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Hall Effect ◽  
Carrier Concentration ◽  
Spark Plasma Sintering ◽  
Valence State ◽  
Hall Effect Measurement ◽  
Precipitation Method ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Co Precipitation

Lu doped polycrystalline In2O3 compounds (x = 0, 0.025, 0.05, 0.10, 0.15) were synthesized by a co-precipitation method followed by the spark plasma sintering processing. Hall Effect measurement indicates that the carrier concentration was drastically decreased with doping, although Lu and In have the same valence state.

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.

Thermoelectric properties of Al–Pd–Re quasicrystal sintered by Spark Plasma Sintering (SPS): effect of improvement of microstructure

2009 ◽  
Vol 224 (1-2) ◽  
Author(s):  
Yoshiki Takagiwa ◽  
Takahiko Kamimura ◽  
Sizuka Hosoi ◽  
Junpei Tamura Okada ◽  
Kaoru Kimura
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Spark Plasma Sintering ◽  
Thermoelectric Properties ◽  
The Other ◽  
Strongly Correlated ◽  
Plasma Sintering ◽  
Icosahedral Quasicrystals ◽  
Spark Plasma

AbstractWe report the thermoelectric properties of poly-grain Al–Pd–Re icosahedral quasicrystals and discuss an effect of improvement of their microstructure. The improvement of microstructure by using Spark Plasma Sintering (SPS) method resulted into a large increase of the electrical conductivity but less increase of the thermal conductivity. The relative density dramatically increased up to more than 90% by SPS. On the other hand, the microstructure itself does not have critical influence on the Seebeck coefficient, which is found to be strongly correlated with

scholarly journals Aluminum/Stainless Steel Clad Materials Fabricated via Spark Plasma Sintering

Materials ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 239 ◽  
Author(s):  
Kwangjae Park ◽  
Dasom Kim ◽  
Kyungju Kim ◽  
Hansang Kwon
Keyword(s):  
Thermal Conductivity ◽  
Stainless Steel ◽  
Thermal Expansion ◽  
Spark Plasma Sintering ◽  
Heat Dissipation ◽  
Coefficient Of Thermal Expansion ◽  
Laser Flash ◽  
High Heat ◽  
Plasma Sintering ◽  
Spark Plasma

Aluminum (Al)/stainless steel (SUS) clad materials were fabricated via the process of spark plasma sintering (SPS) using Al powder/bulk and an SUS sheet. Three Al/SUS clad types were fabricated: powder/bulk (P/B), bulk/bulk (B/B), and bulk/powder/bulk (B/P/B). During the SPS, Al and SUS reacted with each other, and intermetallic compounds were created in the clads. The thermal conductivity and thermal-expansion coefficient were measured using a laser flash analyzer and dynamic mechanical analyzer, respectively. The Al/SUS (P/B) clad had a thermal conductivity of 159.5 W/mK and coefficient of thermal expansion of 15.3 × 10−6/°C. To analyze the mechanical properties, Vickers hardness and three-point bending tests were conducted. The Al/SUS (P/B) clad had a flexural strength of about 204 MPa. The Al/SUS clads fabricated via SPS in this study are suitable for use in applications in various engineering fields requiring materials with high heat dissipation and high heat resistance.

Preparation of Graphene Nanosheets/Copper Composite by Spark Plasma Sintering

2013 ◽  
Vol 833 ◽  
pp. 276-279 ◽  
Author(s):  
Dong Qu ◽  
Fang Zhi Li ◽  
Hai Bin Zhang ◽  
Qian Wang ◽  
Tian Liang Zhou ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Spark Plasma Sintering ◽  
Graphene Nanosheets ◽  
Physical Property Measurement System ◽  
Physical Property ◽  
Laser Flash ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Copper Composite

Graphene nanosheets (GNS)/copper composite has been prepared by spark plasma sintering (SPS). Microstructure of the sintered composite was characterized using scanning electron microscopy (SEM). Thermal conductivity and electrical resistivity properties are evaluated through laser flash apparatus and physical property measurement system. The obtained GNS/copper composite shows a layered structure. The GNS/copper composite prepared by SPS have an anisotropy of thermal conductivity and electrical resistivity.

Preparation and Characterisation of Gd2Zr2O7 Ceramic by Spark Plasma Sintering

2007 ◽  
Vol 280-283 ◽  
pp. 1507-1510 ◽  
Author(s):  
Qiang Xu ◽  
Wei Pan ◽  
Jing Dong Wang ◽  
Long Hao Qi ◽  
He Zhuo Miao ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Relative Density ◽  
Spark Plasma Sintering ◽  
Microstructural Characterization ◽  
Laser Flash ◽  
Flash Method ◽  
Immersion Medium ◽  
Air Atmosphere ◽  
Plasma Sintering ◽  
Spark Plasma

Rare earth Gd2Zr2O7 ceramic was prepared by spark plasma sintering from Gd2O3 and ZrO2 powders. The powders were sintered at 1400°C for 10min. The synthesized ceramic was annealed at 800°C for 2h under air atmosphere. XRD structural and SEM microstructural characterization showed the formation of a single phase material with pyrochlore crystal structure. The relative density of Gd2Zr2O7 ceramic was measured by the Archimedes method with an immersion medium of water and the results revealed that the relative density of the ceramic was 92%. The thermal conductivity of the ceramic was tested by laser flash method from room temperature to 700°C. The result shows the thermal conductivity of Gd2Zr2O7 ceramic is lower than that of 7YSZ.

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