Enhanced thermoelectric properties in PbTe Nanocomposites

2009 ◽  
Vol 1166 ◽  
Author(s):  
Hillary Kirby ◽  
Joshua Martin ◽  
Anuja Datta ◽  
Lidong Chen ◽  
George S. Nolas
Keyword(s):  
Thermoelectric Properties ◽  
Room Temperature ◽  
Room Temperature Resistivity ◽  
Phase Reaction ◽  
Conductivity Measurements ◽  
Temperature Dependent ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Temperature Dependent Thermal Conductivity ◽  
Temperature Resistivity

AbstractDimensional nanocomposites of PbTe with varying carrier concentrations were prepared from undoped and Ag doped PbTe nanocrystals synthesized utilizing an alkaline aqueous solution-phase reaction. The nanocrystals were densified by Spark Plasma Sintering (SPS) for room temperature resistivity, Hall, Seebeck coefficient, and temperature dependent thermal conductivity measurements. The nanocomposites show an enhancement in the thermoelectric properties compared to bulk PbTe with similar carrier concentrations, thus demonstrating a promising approach for enhanced thermoelectric performance.

Synthesis and Thermoelectric Properties of Lead Chalcogenide Nanocomposites

2007 ◽  
Vol 1044 ◽  
Author(s):  
Joshua Martin ◽  
Stevce Stefanoski ◽  
Li Wang ◽  
Lidong Chen ◽  
George S. Nolas
Keyword(s):  
Lead Telluride ◽  
Phase Reaction ◽  
Conductivity Measurements ◽  
Lead Chalcogenide ◽  
Temperature Dependent ◽  
Plasma Sintering ◽  
Nanocrystal Synthesis ◽  
Spark Plasma ◽  
Synthesis Procedure ◽  
Temperature Dependent Resistivity

AbstractDoped lead telluride dimensional nanocomposites were prepared by densifying nanocrystals synthesized employing an alkaline aqueous solution-phase reaction. The nanocrystal synthesis procedure resulted in high product yields of over 2 g per batch. These nanocrystals were then subjected to Spark Plasma Sintering (SPS) for densification. Transport properties were evaluated through temperature dependent resistivity, Hall, Seebeck coefficient, and thermal conductivity measurements. The results for these lead telluride nanocomposites were compared to bulk polycrystalline lead tellurides with similar carrier concentrations.

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.

Preparation and Thermoelectric Properties of Bi Doped Ca3Co4O9 Based Thermoelectric Materials

2018 ◽  
Vol 783 ◽  
pp. 144-147
Author(s):  
Jing Wang ◽  
Qin Chen ◽  
Xia Chun Zhu ◽  
Seok Je Lee ◽  
Kyoung Woo Park ◽  
...  
Keyword(s):  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Phonon Scattering ◽  
Solid Phase ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Sintering Process ◽  
Spin Entropy ◽  
Plasma Sintering ◽  
Spark Plasma

Polycrystalline Ca3-xBixCo4O9 samples have been prepared by solid-phase reaction followed by spark plasma sintering process. The thermoelectric properties have been systematically investigated from room temperature to near 1000K. It is found that the change of the carrier concentration leads to the change of resistivity, which is mainly associated with doping induced point defect phonon scattering. The change of the thermal potential mainly comes from the spin entropy. In addition, polycrystalline Ca3-xBixCo4O9 had a maximum figure of merit of 0.30 at 973 K, which was about 50% higher than Ca3Co4O9. It indicated that doping approach can effectively improve the thermoelectric performance of Ca3Co4O9+δ-based material.

Microstructure and Thermoelectric Properties of CoSb3 Synthesized by MA-SPS Method

2007 ◽  
Vol 336-338 ◽  
pp. 834-837 ◽  
Author(s):  
Wei Shu Liu ◽  
Bo Ping Zhang ◽  
Jing Feng Li ◽  
Heng Wang
Keyword(s):  
Grain Size ◽  
Thermoelectric Properties ◽  
Room Temperature ◽  
Single Phase ◽  
New Combination ◽  
Plasma Sintering ◽  
Average Grain Size ◽  
Spark Plasma ◽  
Xrd Patterns ◽  
Type Conduction

Single-phase polycrystalline CoSb3 skutterudite was prepared through a new combination of mechanical alloying (MA) and spark plasma sintering (SPS). In order to investigate the influence of MA conditions on the microstructure and thermoelectric properties, MA synthesis were carried out under various conditions with different milling times. The powder sample MAed for 6h still consisted of metal Sb, and then transformed to CoSb3 with a little amount of metal Sb and CoSb2 phases after MA for 15h. Further prolonging the MA time resulted in the decomposition of CoSb3 to CoSb2 phase. The average grain size of the SPSed samples decreased from 650nm to 250nm as MA-time was prolonged from 6 to 24h. Lattice parameters estimated form XRD patterns increase with the increasing MA time. All samples SPSed at 600°C for holding 5 min show an n-type conduction. The electrical resistivity was 1030, 895, 410, 260 μm for the samples from the MA-derived powders with MA-time of 6, 15, 24 and 33h at room temperature, respectively, then reduced to 60 μm at 400°C for all samples. An optimum MA time is 24 h in which the sample shows the highest power factor 612μW/m*K2 at 150°C.

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.

scholarly journals Thermoelectric Properties of Scandium Sesquitelluride

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 734 ◽  
Author(s):  
Dean Cheikh ◽  
Kathleen Lee ◽  
Wanyue Peng ◽  
Alexandra Zevalkink ◽  
Jean-Pierre Fleurial ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Lattice Thermal Conductivity ◽  
Structure Type ◽  
Chemical Similarity ◽  
Temperature Dependent ◽  
Figures Of Merit ◽  
Lanthanide Series ◽  
Plasma Sintering ◽  
Spark Plasma

Rare-earth (RE) tellurides have been studied extensively for use in high-temperature thermoelectric applications. Specifically, lanthanum and praseodymium-based compounds with the Th3P4 structure type have demonstrated dimensionless thermoelectric figures of merit (zT) up to 1.7 at 1200 K. Scandium, while not part of the lanthanide series, is considered a RE element due to its chemical similarity. However, little is known about the thermoelectric properties of the tellurides of scandium. Here, we synthesized scandium sesquitelluride (Sc2Te3) using a mechanochemical approach and formed sintered compacts through spark plasma sintering (SPS). Temperature-dependent thermoelectric properties were measured from 300–1100 K. Sc2Te3 exhibited a peak zT = 0.3 over the broad range of 500–750 K due to an appreciable power factor and low-lattice thermal conductivity in the mid-temperature range.

scholarly journals Temperature-dependent thermal properties of spark plasma sintered alumina

2017 ◽  
Vol 49 (2) ◽  
pp. 117-128 ◽  
Author(s):  
Nouari Saheb ◽  
Umer Hayat
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Specific Heat ◽  
Room Temperature ◽  
Alumina Powder ◽  
Temperature Dependent ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Sintering Method

In this work, we report temperature-dependent thermal properties of alumina powder and bulk alumina consolidated by spark plasma sintering method. The properties were measured between room temperature and 250?C using a thermal constants analyzer. Alumina powder had very low thermal properties due to the presence of large pores and absence of bonding between its particles. Fully dense alumina with a relative density of 99.6 % was obtained at a sintering temperature of 1400?C and a holding time of 10 min. Thermal properties were found to mainly dependent on density. Thermal conductivity, thermal diffusivity, and specific heat of the fully dense alumina were 34.44 W/mK, 7.62 mm2s-1, and 1.22 J/gK, respectively, at room temperature. Thermal conductivity and thermal diffusivity decreased while specific heat increased with the increase in temperature from room temperature to 250?C.

Enhanced Thermoelectric Properties of [Ca2CoO3-δ]0.62CoO2 Polycrystalline Bulk by Control of Microstructure and Oxygen Content

2002 ◽  
Vol 755 ◽  
Author(s):  
M. Sano ◽  
S. Horii ◽  
I. Matsubara ◽  
R. Funahashi ◽  
M. Shikano ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Seebeck Coefficient ◽  
Oxygen Content ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Room Temperature ◽  
Magnetic Alignment ◽  
Systematic Change ◽  
Plasma Sintering ◽  
Spark Plasma

ABSTRACTWe report preparation of highly grain-aligned and densified [Ca2CoO3-δ]0.62CoO2 bulks and a change of thermoelectric performance for their bulks with different oxygen deficiencies (dgrl). The highly c-axis aligned and highly densified samples which showed low electronic resistivities at room temperature, were obtained by combination of magnetic alignment and spark plasma sintering methods. Electronic resistivity p and Seebeck coefficient S along the ab plane were systematically changed with oxygen contents and a power factor was consequently enhanced up to 3.5×10--6 Wcm-1K-2 at 300K for the sample annealed at 500°C in air. Moreover, the magnetic properties also showed a systematic change with oxygen contents.

scholarly journals The Extrusion and SPS of Zirconium–Copper Powders and Studies of Selected Mechanical Properties

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3560
Author(s):  
Tomasz Skrzekut ◽  
Grzegorz Boczkal ◽  
Adam Zwoliński ◽  
Piotr Noga ◽  
Lucyna Jaworska ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Intermetallic Compounds ◽  
Room Temperature ◽  
Intermetallic Phase ◽  
Extrusion Process ◽  
Strength Properties ◽  
Plasma Sintering ◽  
Copper Powders ◽  
Spark Plasma ◽  
Zirconium Copper

Zr-2.5Cu and Zr-10Cu powder mixtures were consolidated in the extrusion process and using the spark plasma sintering technique. In these studies, material tests were carried out in the fields of phase composition, microstructure, hardness and tensile strength for Zr-Cu materials at room temperature (RT) and 400 °C. Fractography analysis of materials at room temperature and 400 °C was carried out. The research took into account the anisotropy of the materials obtained in the extrusion process. For the nonequilibrium SPS process, ZrCu2 and Cu10Zr7 intermetallic compounds formed in the material at sintering temperature. Extruded materials were composed mainly of α-Zr and ZrCu2. The presence of intermetallic compounds affected the reduction in the strength properties of the tested materials. The highest strength value of 205 MPa was obtained for the extruded Zr-2.5Cu, for which the samples were cut in the direction of extrusion. For materials with 10 wt.% copper, more participation of the intermetallic phase was formed, which lowered the mechanical properties of the obtained materials. In addition to brittle intermetallic phases, the materials were characterized by residual porosity, which also reduced the strength properties.

scholarly journals Effect of Powder Heat Treatment on Chemical Composition and Thermoelectric Properties of Bismuth Antimony Telluride Alloys Fabricated by Combining Water Atomization and Spark Plasma Sintering

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2993
Author(s):  
Dong-won Shin ◽  
Peyala Dharmaiah ◽  
Jun-Woo Song ◽  
Soon-Jik Hong
Keyword(s):  
Spark Plasma Sintering ◽  
Thermoelectric Properties ◽  
Hole Concentration ◽  
Bismuth Antimony Telluride ◽  
Plasma Sintering ◽  
Heat Treated ◽  
Water Atomization ◽  
Powder Samples ◽  
Different Temperatures ◽  
Spark Plasma

In this work, Bi0.5Sb1.5Te3 materials were produced by an economically viable and time efficient water atomization process. The powder samples were heat treated at different temperatures (673 K, 723 K, 743 K, 773 K, 803 K, and 823 K) followed by spark plasma sintering (SPS). It was found that the Te evaporated slightly at 723 K and 743 K and became dominated at 773 K, 803 K, and 823 K, which severely influences the thermoelectric properties. The electrical conductivity was significantly improved for over 803 K heat treated samples due to the remarkable improvement in hole concentration. The power factor values for the 803 K and 823 K samples were significantly larger at T > 350 K compared to other samples. Consequently, the peak ZT of 0.92 at 350 K was obtained for the 803 K sample, which could be useful in commercial thermoelectric power generation.

Sign in / Sign up

Export Citation Format

Share Document