scholarly journals The use of materials based on Si3N4 in the composition of composites for the design of high-temperature thermoelectric generators

2020 ◽  
pp. 7-14
Author(s):  
V.V. Tsygoda ◽  
V.Ya. Petrovskiy
Keyword(s):  
Thermal Conductivity ◽  
High Temperature ◽  
Figure Of Merit ◽  
Negative Temperature ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Generators ◽  
Thermoelectric Figure ◽  
Coefficient Of Thermal Conductivity ◽  
Materials Used ◽  
First Time

The possibility of reducing the thermal conductivity of silicon nitride as a basis of high-temperature electrical converters was investigated in the thesis. Also, the values of thermoelectric figure of merit and efficiency of thermoelectric current generator for the case of refractory oxygen-free composites were simulated. During the study, the dependence between the m coefficient, which determines the maximum possible efficiency of the thermoelectric generator and the ZT thermoelectric figure of merit, was determined. It was shown that the coefficient of thermal conductivity of the studied materials ranges from 1,2 to 4·106 m2/s and is characterized by a negative temperature coefficient over the entire temperature range. It was found that the thermal conductivity of Si3N4-based materials varies from 2,1 to 5,1 W/(m·K) depending on the type of sintering activator. The use of Al2O3 as an activator makes it possible to obtain a 25% lower thermal conductivity value comparing to materials with the addition of MgO. For the first time, it was proved that currently it is not possible to achieve an efficiency of 0,5hT in Si3N4-based materials used as a composite basis for high-temperature thermoelectric generators development.

Thermoelectric Properties of Semiconducting Intermetallic Compounds: FeGa3and RuGa3

2003 ◽  
Vol 793 ◽  
Author(s):  
Y. Amagai ◽  
A. Yamamoto ◽  
C. H. Lee ◽  
H. Takazawa ◽  
T. Noguchi ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
High Temperature ◽  
Seebeck Coefficient ◽  
Transport Properties ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
High Seebeck Coefficient

ABSTRACTWe report transport properties of polycrystalline TMGa3(TM = Fe and Ru) compounds in the temperature range 313K<T<973K. These compounds exhibit semiconductorlike behavior with relatively high Seebeck coefficient, electrical resistivity, and Hall carrier concentrations at room temperature in the range of 1017- 1018cm−3. Seebeck coefficient measurements reveal that FeGa3isn-type material, while the Seebeck coefficient of RuGa3changes signs rapidly from large positive values to large negative values around 450K. The thermal conductivity of these compounds is estimated to be 3.5Wm−1K−1at room temperature and decreased to 2.5Wm−1K−1for FeGa3and 2.0Wm−1K−1for RuGa3at high temperature. The resulting thermoelectric figure of merit,ZT, at 945K for RuGa3reaches 0.18.

Thermoelectric properties of (Bi,Pb)–Sr–Co–O oxide

2000 ◽  
Vol 15 (2) ◽  
pp. 382-386 ◽  
Author(s):  
Woosuck Shin ◽  
Norimitsu Murayama
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
High Temperature ◽  
Single Crystal ◽  
Figure Of Merit ◽  
Polycrystalline Sample ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
Sinter Forging ◽  
Thermoelectric Application

Electrical conductivity and thermopower of Bi2Sr3Co2Ox sintered bodies were first investigated in the temperature range 440–1060 K in air for high-temperature thermoelectric application. The samples fabricated by the sinter-forging method increased their bulk densities and electrical conductivity. The value of thermopower and the temperature dependence of electrical conductivity of the sinter-forged samples were close to that of the single crystal. Evaluating the thermal conductivity of the polycrystalline sample, we calculated a thermoelectric figure of merit Z to be 0.107 × 10−3 K−1 at 1060 K.

scholarly journals Measuring Device and Material ZT in a Thin-Film Si-Based Thermoelectric Microgenerator

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 653 ◽  
Author(s):  
Pablo Ferrando-Villalba ◽  
Antonio Pablo Pérez-Marín ◽  
Llibertat Abad ◽  
Gustavo Gonçalves Dalkiranis ◽  
Aitor F. Lopeandia ◽  
...  
Keyword(s):  
Thin Film ◽  
Thermal Conductivity ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Generators ◽  
Thermoelectric Figure ◽  
Measuring Device ◽  
Different Temperatures ◽  
Si Thin Film

Thermoelectricity (TE) is proving to be a promising way to harvest energy for small applications and to produce a new range of thermal sensors. Recently, several thermoelectric generators (TEGs) based on nanomaterials have been developed, outperforming the efficiencies of many previous bulk generators. Here, we presented the thermoelectric characterization at different temperatures (from 50 to 350 K) of the Si thin-film based on Phosphorous (n) and Boron (p) doped thermocouples that conform to a planar micro TEG. The thermocouples were defined through selective doping by ion implantation, using boron and phosphorous, on a 100 nm thin Si film. The thermal conductivity, the Seebeck coefficient, and the electrical resistivity of each Si thermocouple was experimentally determined using the in-built heater/sensor probes and the resulting values were refined with the aid of finite element modeling (FEM). The results showed a thermoelectric figure of merit for the Si thin films of z T = 0.0093, at room temperature, which was about 12% higher than the bulk Si. In addition, we tested the thermoelectric performance of the TEG by measuring its own figure of merit, yielding a result of ZT = 0.0046 at room temperature.

Thermoelectric Properties of BaxCo4Sb12 Prepared by High Pressure and High Temperature

2011 ◽  
Vol 415-417 ◽  
pp. 1615-1619
Author(s):  
Bing Ke Qin ◽  
Yong Hua Ji ◽  
Zhi Li ◽  
Xiao Peng Jia
Keyword(s):  
Thermal Conductivity ◽  
High Pressure ◽  
High Temperature ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
Filled Skutterudite

Polycrystalline filled Skutterudite compounds BaxCo4Sb12(0-x-0.5) are synthesized by high pressure and high temperature （HPHT） technique. The thermal conductivity for CoSb3is depressed significantly by Ba-filling combined HPHT technique. The value of 1.25 Wm-1K-1for Ba0.372Co4Sb12is obtained at 633K. The dimensionless thermoelectric figure of merit ZT, increases with temperature increasing and reaches a maximal value of 1.01 at 663 K.

scholarly journals Thermoelectric properties of Ni0.15Co3.85Sb12 and Fe0.2Ni0.15Co3.65Sb12 skutterudites prepared by HPHT method

2017 ◽  
Vol 35 (3) ◽  
pp. 496-500 ◽  
Author(s):  
Lingjiao Kong ◽  
Hongan Ma ◽  
Yuewen Zhang ◽  
Xin Guo ◽  
Bing Sun ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Conductivity ◽  
High Pressure ◽  
High Temperature ◽  
Transport Properties ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
Synthesis Time

AbstractN-type polycrystalline skutterudite compounds Ni0.15Co3.85Sb12 and Fe0.2Ni0.15Co3.65Sb12 with the bcc crystal structure were synthesized by high pressure and high temperature (HPHT) method. The synthesis time was sharply reduced to approximately half an hour. Typical microstructures connected with lattice deformations and dislocations were incorporated in the samples of Ni0.15Co3.85Sb12 and Fe0.2Ni0.15Co3.65Sb12 after HPHT. Electrical and thermal transport properties were meticulously researched in the temperature range of 300 K to 700 K. The Fe0.2Ni0.15Co3.65Sb12 sample shows a lower thermal conductivity than that of Ni0.15Co3.85Sb12. The dimensionless thermoelectric figure-of-merit (zT) reaches the maximal values of 0.52 and 0.35 at 600 K and 700 K respectively, for Ni0.15Co3.85Sb12 and Fe0.2Ni0.15Co3.65Sb12 samples synthesized at 1 GPa.

scholarly journals Synthesis and Thermoelectric Properties of PbTe-SnTe Solid Solutions

2016 ◽  
Vol 17 (4) ◽  
pp. 570-574 ◽  
Author(s):  
I.V. Horichok ◽  
L.I. Nykyruy ◽  
M.O. Galushchak ◽  
S.I. Mudrij ◽  
T.O. Semko ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electromotive Force ◽  
Figure Of Merit ◽  
Specific Electrical Conductivity ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
Pressing Method ◽  
X Ray ◽  
Coefficient Of Thermal Conductivity ◽  
Thermoelectric Parameters

There are presents X-ray results and measurements of thermoelectric parameters (thermoelectric electromotive force α, specific electrical conductivity σ, and coefficient of thermal conductivity k) for materials on the base of PbTe-SnTe system. The dimensionless thermoelectric figure of merit ZT ≈ 0,3 received for thermoelectric samples p-Pb0.4Sn0.6Te obtained by cold pressing method in complex with annealing.

scholarly journals NANOCOMPOSITES TO ENHANCE ZT IN THERMOELECTRICS

2007 ◽  
Vol 1044 ◽  
Author(s):  
Mildred Dresselhaus ◽  
Gang Chen ◽  
Zhifeng Ren ◽  
Jean-Pierre Fleurial ◽  
Pawan Gogna ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Power Generation ◽  
High Temperature ◽  
Figure Of Merit ◽  
Scale Up ◽  
Simultaneous Increase ◽  
Thermoelectric Figure Of Merit ◽  
Materials Synthesis ◽  
Thermoelectric Figure ◽  
General Terms

AbstractThe concept of using “self-assembled” and “force-engineered” nanostructures to enhance the thermoelectric figure of merit relative to bulk homogeneous and composite materials is presented in general terms. Specific application is made to the Si-Ge system for use in power generation at high temperature. The scientific advantages of the nanocomposite approach for the simultaneous increase in the power factor and decrease of the thermal conductivity are emphasized along with the practical advantages of having bulk samples for property measurements and a straightforward path to scale-up materials synthesis and integration of nanostructured materials into thermoelectric cooling and power generation devices.

Influence of multi-sintering on the thermoelectric properties of Bi2Sr2Co2Oy ceramics

2019 ◽  
Vol 34 (02) ◽  
pp. 2050019 ◽  
Author(s):  
Y. Zhang ◽  
M. M. Fan ◽  
C. C. Ruan ◽  
Y. W. Zhang ◽  
X.-J. Li ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Phonon Scattering ◽  
Sintered Sample ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
The Third ◽  
Ceramic Samples ◽  
Optimum Formula

[Formula: see text] ceramic samples have a structure similar to phonon glass electronic crystals, and their thermoelectric properties can be effectively adjusted through repeated grinding and sintering. The results show that multi-sintering can make their grain refined and increase their grain boundary, which will effectively increase density and phonon scattering. Finally, multi-sintering can reduce the resistivity and thermal conductivity, thus obviously improve thermoelectric figure of merit [Formula: see text] of [Formula: see text]. The optimum [Formula: see text] value of 0.26 is achieved at 923 K by the third sintered sample.

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.

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