Thermoelectric Properties of Two Ternary Tellurides

1998 ◽  
Vol 545 ◽  
Author(s):  
Jeff W. Sharp ◽  
Brian C. Sales ◽  
David G. Mandrus ◽  
Bryan C. Chakoumakos
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Lattice Thermal Conductivity ◽  
Atomic Displacement ◽  
Thermal Expansion Coefficients ◽  
Good Figure ◽  
Atomic Displacement Parameters ◽  
Binary Compounds ◽  
P Type

AbstractWe present initial assessments of the thermoelectric properties of two ternary tellurides with known crystal structures, Tl2GeTeM5 and Tl2SnTe5. Tl2SnTe5 appears to have a p-type figure of merit about the same as that of Bi2Te3, the best thermoelectric material among binary compounds. A good figure of merit is possible because the lattice thermal conductivity is very low. Based on neutron diffraction data, we have calculated atomic displacement parameters and thermal expansion coefficients. The atomic displacement parameters give some understanding of the low lattice thermal conductivity.

scholarly journals Bipolar doping and thermoelectric properties of Zintl arsenide Eu5In2As6

2021 ◽  
Author(s):  
Naoki Tomitaka ◽  
Yosuke Goto ◽  
Kota Morino ◽  
Kazuhisa Hoshi ◽  
Yuki Nakahira ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Thermoelectric Properties ◽  
High Performance ◽  
Figure Of Merit ◽  
Lattice Thermal Conductivity ◽  
High Resistivity ◽  
Dimensionless Figure Of Merit ◽  
Recent Developments ◽  
P Type

Zintl compounds exhibit promising thermoelectric properties because of the feasibility of the chemical tuning of their electrical and thermal transport. While most Zintl pnictides are known to show p-type polarity, recent developments in high-performance n-type Mg3Sb2-based thermoelectric materials have encouraged further identification of n-type Zintl pnictides. In this study, we demonstrate the bipolar dopability of the Zintl arsenide Eu5In2As6. The electrical resistivity at 300 K with n-type polarity was decreased to 7.6 x 10^-1 ohmcm using La as an electron dopant. In contrast to the relatively high resistivity of n-type Eu5In2As6, the p-type resistivity at 300 K was decreased to 5.9 x 10^-3 ohmcm with a carrier concentration of 2.8 x 10^20 /cm3 using Zn as a hole dopant. This doping asymmetry is discussed in terms of the weighted mobility of electrons and holes. Furthermore, a very low lattice thermal conductivity of 0.7 W/mK was observed at 773 K, which is comparable to that of the Sb-containing analogue Eu5In2Sb6. The dimensionless figure of merit ZT = 0.29 at 773 K for Zn-doped p-type Eu5In2As6. This study shows that bipolar dopable Eu5In2As6 can be a platform to facilitate a better understanding of the doping asymmetry in Zintl pnictides.

Effects of Ce filling fraction and Fe content on the thermoelectric properties of Co-rich CeyFexCo4−xSb12

2001 ◽  
Vol 16 (3) ◽  
pp. 837-843 ◽  
Author(s):  
Xinfeng Tang ◽  
Lidong Chen ◽  
Takashi Goto ◽  
Toshio Hirai
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Single Phase ◽  
Lattice Thermal Conductivity ◽  
Hole Concentration ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
Filling Fraction ◽  
Fe Content

Single-phase filled skutterudite compounds, CeyFexCo4−xSb12 (x = 0 to 3.0, y = 0 to 0.74), were synthesized by a melting method. The effects of Fe content and Ce filling fraction on the thermoelectric properties of CeyFexCo4−xSb12 were investigated. The lattice thermal conductivity of Ce-saturated CeyFexCo4−xSb12, y being at the maximum corresponding to x, decreased with increasing Fe content (x) and reached its minimum at about x = 1.5. When x was 1.5, lattice thermal conductivity decreased with increasing Ce filling fraction till y = 0.3 and then began to increase after reaching the minimum at y = 0.3. Hole concentration and electrical conductivity of Cey Fe1.5Co2.5Sb12 decreased with increasing Ce filling fraction. The Seebeck coefficient increased with increasing Ce filling fraction. The greatest dimensionless thermoelectric figure of merit T value of 1.1 was obtained at 750 K for the composition of Ce0.28Fe1.52Co2.48Sb12.

Thermoelectric Properties of K2Bi8−xSbxSe13Solid Solutions and Se Doping

2001 ◽  
Vol 691 ◽  
Author(s):  
Theodora Kyratsi ◽  
Jeffrey S. Dyck ◽  
Wei Chen ◽  
Duck-Young Chung ◽  
Ctirad Uher ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Charge Transport ◽  
Transport Properties ◽  
Thermoelectric Properties ◽  
Solid Solutions ◽  
Figure Of Merit ◽  
Lattice Thermal Conductivity ◽  
Se Doping ◽  
Mass Fluctuation ◽  
Thermal Conductivities

ABSTRACTOur efforts to improve the thermoelectric properties of β-K2Bi8Se13, led to systematic studies of solid solutions of the type β-K2Bi8−xSbxSe13. The charge transport properties and thermal conductivities were studied for selected members of the series. Lattice thermal conductivity decreases due to the mass fluctuation generated in the lattice by the mixed occupation of Sb and Bi atoms. Se excess as a dopant was found to increase the figure-of merit of the solid solutions.

The Influence of RuO2 Addition on the Thermoelectric Properties of BiSbTe Alloys

2012 ◽  
Vol 512-515 ◽  
pp. 1651-1654 ◽  
Author(s):  
Yu Kun Xiao ◽  
Zhi Xiang Li ◽  
Jun Jiang ◽  
Sheng Hui Yang ◽  
Ting Zhang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Lattice Thermal Conductivity ◽  
Combined Process ◽  
Plasma Sintering ◽  
The Matrix ◽  
Spark Plasma ◽  
Xrd Patterns ◽  
Factor Α ◽  
P Type

P-type BiSbTe/RuO2 composite was fabricated using a combined process of melting and spark plasma sintering. The XRD patterns showed that RuO2 reacted with the matrix for the RuO2 content of 1.0 wt% and 4.0 wt% samples. The measured thermoelectric properties showed that the highest electrical conductivity was obtained for the sample with 2.0 wt% RuO2. The power factor (α2σ/κ) decreased with the increase of RuO2 below 450 K. The lattice thermal conductivity was lower than that of BiSbTe over the whole temperature range for BiSbTe/2.0 wt% RuO2.

Thermoelectric Properties of CoSb3-based Skutterudite Compounds

2010 ◽  
Vol 1267 ◽  
Author(s):  
Adul Harnwunggmoung ◽  
Ken Kurosaki ◽  
Hiroaki Muta ◽  
Shinsuke Yamanaka
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Lattice Thermal Conductivity ◽  
Filling Ratio ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
Alloy Scattering ◽  
Skutterudite Compound

AbstractCoSb3 is known as a skutterudite compound that could exhibit high thermoelectric figure of merit. However, the thermal conductivity of CoSb3 is relatively high. In order to enhance the thermoelectric performance of this compound, we tried to reduce the thermal conductivity of CoSb3 by substitution of Rh for Co and by Tl-filling into the voids. The polycrystalline samples of (Co,Rh)Sb3 and Tl-filled CoSb3 were prepared and the thermoelectric properties such as the Seebeck coefficient, electrical resistivity, and thermal conductivity were measured in the temperature range from room temperature to 750 K. The Rh substitution for Co reduced the lattice thermal conductivity, due to the alloy scattering effect. The minimum value of the lattice thermal conductivity was 4 Wm-1K-1 at 750 K obtained for (Co0.7Rh0.3)Sb3. Also the lattice thermal conductivity rapidly decreased with increasing the Tl-filling ratio. T10.25Co4Sb12 exhibited the best ZT values; the maximum ZT was 0.9 obtained at 600 K.

Thermoelectric Properties of Bi2Te3-ySey Bulk Materials Synthesized by Melting-Grinding Process

2018 ◽  
Vol 773 ◽  
pp. 145-151
Author(s):  
Min Soo Park ◽  
Gook Hyun Ha ◽  
Hye Young Koo ◽  
Yong Ho Park
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Thermal Characteristics ◽  
Grinding Process ◽  
Alloy Scattering ◽  
Temperature Range ◽  
P Type ◽  
Optimal Effect

The Bi–Te thermoelectric system shows an excellent figure of merit (ZT) near room temperature. Research on increasing the ZT value for n‑type Bi–Te is imperative because the thermoelectric properties of this compound are inferior to those of the p-type material. For this purpose, n-type Bi2Te3-ySey powders with various amounts of Se dopant (0.3 ≤ y ≤ 0.6) were synthesized by a vacuum melting-grinding process to improve the physical properties. The ZT value of the sintered bodies was investigated in the temperature range of 298–423 K with regard to the electrical and thermal characteristics. As the Se content increased, the electrical conductivity decreased owing to a reduction in the carrier concentration, which improved the overall value of ZT. The thermal conductivity clearly decreased as the Se content increased in the temperature range of 298–373 K due to increased alloy scattering, as well as a reduction in the lattice thermal conductivity caused by crystal grain boundary scattering. At room temperature, Bi2Te2.7Se0.3 (y = 0.3) exhibited the highest ZT of 0.85. At increased temperatures, the ZT value was highest for Bi2Te2.55Se0.45 (y = 0.45), indicating that the optimal effect of the Se dopants varies depending on the temperature range.

Improved thermoelectric properties of gadolinium intercalated compounds GdxTiS2 at the temperaturesfrom 5 to 310 K

2006 ◽  
Vol 21 (2) ◽  
pp. 480-483 ◽  
Author(s):  
D. Li ◽  
X.Y. Qin ◽  
J. Zhang
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Lattice Thermal Conductivity ◽  
Substantial Decrease ◽  
Intercalated Compounds

The thermoelectric properties of Gd intercalated compounds GdxTiS2 have been investigated at the temperatures from 5 to 310 K. The results indicate that Gd intercalation into TiS2 leads to substantial decrease of both its electrical resistivity and its lattice thermal conductivity κL (κL is lowered by 20% and 46% at 300 K for x = 0.025 and 0.05, respectively). Specially, as compared to the pristine TiS2 the figure of merit ZT of the intercalated compound GdxTiS2 has been improved at all temperatures investigated, and specifically, the ZT value of Gd0.05TiS2 at 300 K is about three times as large as that of TiS2.

Thermal Conductivity of Zn4−xCdxSb3 Solid Solutions

1997 ◽  
Vol 478 ◽  
Author(s):  
T. Caillat ◽  
A. Borshchevsky ◽  
J. -P. Fleurial
Keyword(s):  
Thermal Conductivity ◽  
High Performance ◽  
Figure Of Merit ◽  
Lattice Thermal Conductivity ◽  
State Of The Art ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
Jet Propulsion ◽  
P Type ◽  
Electrical Conductors

Abstractβ-Zn4Sb3 was recently identified at the Jet Propulsion Laboratory as a new high performance p-type thermoelectric material with a maximum dimensionless thermoelectric figure of merit ZT of 1.4 at a temperature of 673K. A usual approach, used for many state-of-the-art thermoelectric materials, to further improve ZT values is to alloy β-Zn4Sb3 with isostructural compounds because of the expected decrease in lattice thermal conductivity. We have grown Zn4−xCdxSb3 crystals with 0.2≤x<1.2 and measured their thermal conductivity from 10 to 500K. The thermal conductivity values of Zn4−xCdxSb3 alloys are significantly lower than those measured for β-Zn4Sb3 and are comparable to its calculated minimum thermal conductivity. A strong atomic disorder is believed to be primarily at the origin of the very low thermal conductivity of these materials which are also fairly good electrical conductors and are therefore excellent candidates for thermoelectric applications.

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