Preparation and Thermoelectric Properties of (Ca1-x-yKxBiy)3Co4O9 Ceramic

2008 ◽  
Vol 368-372 ◽  
pp. 559-561 ◽  
Author(s):  
Hao Ming Hu ◽  
Yuan Deng ◽  
Jian Li ◽  
Guang Sheng Wang
Keyword(s):  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Transport Properties ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Room Temperature ◽  
Raw Materials ◽  
Sol Gel ◽  
Sintering Process ◽  
Conventional Sintering

The precursor of (Ca1-x-yKxBiy)3Co4O9 was synthesized by sol-gel method using nitrate salts as raw materials and citrate acid as agent. The final product was obtained after the precursor was calcined at 800°C for 4 h. The polycrystalline bulk samples were fabricated by a conventional sintering process at 900°C for 12 h. XRD and SEM were used to characterize the microstructures and the composition of the samples. The transport properties of the samples at room temperature were determined by measuring electrical conductivity and Seebeck coefficient. The Bi and K-doped samples show an excellent transport properties even at room temperature. The value of power factor of (Ca0.90K0.075Bi0.025)3Co4O9 reaches 1.42×10-4Wm-1K-2 at 293K, close to the performance of pure Ca3Co4O9 at 1000K.

The Influence of Silicon Dopant and Processing on Thermoelectric Properties of B4C Ceramics

1998 ◽  
Vol 545 ◽  
Author(s):  
Ke-Feng Cai ◽  
Ce-Wen Nan ◽  
Xin-Min Min
Keyword(s):  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Hot Pressing ◽  
Figure Of Merit ◽  
Room Temperature ◽  
A Value ◽  
Si Doped

AbstractB4C ceramics doped with various content of Si (0 to 2.03 at%) are prepared via hot pressing. The composition and microstructure of the ceramics are characterized by means of XRD and EPMA. Their electrical conductivity and Seebeck coefficient of the samples are measured from room temperature up to 1500K. The electrical conductivity increases with temperature, and more rapidly after 1300K; the Seebeck coefficient of the ceramics also increases with temperature and rises to a value of about 320μVK−1. The value of the figure of merit of Si-doped B4C rises to about 4 × 10−4K−1 at 1500K.

scholarly journals Preparation and Thermoelectric Properties of Graphite/poly(3,4-ethyenedioxythiophene) Nanocomposites

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2849 ◽  
Author(s):  
Yong Du ◽  
Haixia Li ◽  
Xuechen Jia ◽  
Yunchen Dou ◽  
Jiayue Xu ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Oxidative Polymerization ◽  
Polymerization Process ◽  
Measurement Temperature ◽  
Temperature Range ◽  
Different Content

Graphite/poly(3,4-ethyenedioxythiophene) (PEDOT) nanocomposites were prepared by an in-situ oxidative polymerization process. The electrical conductivity and Seebeck coefficient of the graphite/PEDOT nanocomposites with different content of graphite were measured in the temperature range from 300 K to 380 K. The results show that as the content of graphite increased from 0 to 37.2 wt %, the electrical conductivity of the nanocomposites increased sharply from 3.6 S/cm to 80.1 S/cm, while the Seebeck coefficient kept almost the same value (in the range between 12.0 μV/K to 15.1 μV/K) at 300 K, which lead to an increased power factor. The Seebeck coefficient of the nanocomposites increased from 300 K to 380 K, while the electrical conductivity did not substantially depend on the measurement temperature. As a result, a power factor of 3.2 μWm−1 K−2 at 380 K was obtained for the nanocomposites with 37.2 wt % graphite.

scholarly journals Annealing Effect on the Thermoelectric Properties of Bi2Te3Thin Films Prepared by Thermal Evaporation Method

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Jyun-Min Lin ◽  
Ying-Chung Chen ◽  
Chi-Pi Lin
Keyword(s):  
Thin Films ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Thermal Evaporation ◽  
Thermal Evaporation Method ◽  
Si Substrates ◽  
Seebeck Coefficients

Bismuth telluride-based compounds are known to be the best thermoelectric materials within room temperature region, which exhibit potential applications in cooler or power generation. In this paper, thermal evaporation processes were adopted to fabricate the n-type Bi2Te3thin films on SiO2/Si substrates. The influence of thermal annealing on the microstructures and thermoelectric properties of Bi2Te3thin films was investigated in temperature range 100–250°C. The crystalline structures and morphologies were characterized by X-ray diffraction and field emission scanning electron microscope analyses. The Seebeck coefficients, electrical conductivity, and power factor were measured at room temperature. The experimental results showed that both the Seebeck coefficient and power factor were enhanced as the annealing temperature increased. When the annealing temperature increased to 250°C for 30 min, the Seebeck coefficient and power factor of n-type Bi2Te3-based thin films were found to be about −132.02 μV/K and 6.05 μW/cm·K2, respectively.

scholarly journals Влияние легирования ванадием на термоэлектрические свойства сплавов Гейслера Fe-=SUB=-2-=/SUB=-Ti-=SUB=-1-x-=/SUB=-V-=SUB=-x-=/SUB=-Sn

2019 ◽  
Vol 53 (6) ◽  
pp. 777
Author(s):  
А.И. Таранова ◽  
А.П. Новицкий ◽  
А.И. Воронин ◽  
С.В. Таскаев ◽  
В.В. Ховайло
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Experimental Study ◽  
Seebeck Coefficient ◽  
Transport Properties ◽  
Thermoelectric Properties ◽  
Pristine Sample ◽  
Electrical Conductivity Behavior ◽  
P Type ◽  
Conductivity Behavior

In this work the results of an experimental study of Fe2Ti1-xVxSn alloys (x = 0; 0.06; 0.15; 0.2) are presented. According to the temperature dependencies of the electrical conductivity, Seebeck coefficient and thermal conductivity, it is established, that the studied compositions exhibit transport properties typical for semiconductors. The substitution of V at the Ti site leads to a change of the p-type electrical conductivity behavior to n-type; the pristine sample of Fe2TiSn has the best thermoelectric properties.

scholarly journals Thermoelectric Properties of Ca3Co2−xMnxO6 (x = 0.05, 0.2, 0.5, 0.75, and 1)

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 497 ◽  
Author(s):  
Nikola Kanas ◽  
Sathya Singh ◽  
Magnus Rotan ◽  
Temesgen Desissa ◽  
Tor Grande ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Self Assembly ◽  
Intermediate Phase ◽  
Small Polaron ◽  
Solid State Method ◽  
Polaron Hopping ◽  
Seebeck Coefficients ◽  
Conventional Sintering

High-temperature instability of the Ca3Co4−yO9+δ and CaMnO3−δ direct p-n junction causing the formation of Ca3Co2−xMnxO6 has motivated the investigation of the thermoelectric performance of this intermediate phase. Here, the thermoelectric properties comprising Seebeck coefficient, electrical conductivity, and thermal conductivity of Ca3Co2−xMnxO6 with x = 0.05, 0.2, 0.5, 0.75, and 1 are reported. Powders of the materials were synthesized by the solid-state method, followed by conventional sintering. The material Ca3CoMnO6 (x = 1) demonstrated a large positive Seebeck coefficient of 668 μV/K at 900 °C, but very low electrical conductivity. Materials with compositions with x < 1 had lower Seebeck coefficients and higher electrical conductivity, consistent with small polaron hopping with an activation energy for mobility of 44 ± 6 kJ/mol and where both the concentration and mobility of hole charge carriers were proportional to 1−x. The conductivity reached about 11 S·cm−1 at 900 °C for x = 0.05. The material Ca3Co1.8Mn0.2O6 (x = 0.2) yielded a maximum zT of 0.021 at 900 °C. While this value in itself is not high, the thermodynamic stability and self-assembly of Ca3Co2−xMnxO6 layers between Ca3Co4−yO9+δ and CaMnO3−δ open for new geometries and designs of oxide-based thermoelectric generators.

scholarly journals Thermoelectric Properties of Bi2Te3: CuI and the Effect of Its Doping with Pb Atoms

2017 ◽  
Author(s):  
Mi-Kyung Han ◽  
Yingshi Jin ◽  
Da-Hee Lee ◽  
Sung-Jin Kim
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Transport Properties ◽  
Carrier Concentration ◽  
Thermoelectric Properties ◽  
Thermal Transport ◽  
Co Doping ◽  
Thermal Transport Properties ◽  
Co Doped

In order to understand the effect of Pb-CuI co-doping on the thermoelectric performance of Bi2Te3, n-type Bi2Te3 co-doped with x at% CuI and 1/2x at% Pb (x = 0, 0.01, 0.03, 0.05, 0.07, and 0.10) were prepared via high temperature solid state reaction and consolidated using spark plasma sintering. Electron and thermal transport properties, i.e., electrical conductivity, carrier concentration, Hall mobility, Seebeck coefficient, and thermal conductivity, of CuI-Pb co-doped Bi2Te3 were measured in the temperature range from 300 K to 523 K and compared to corresponding x% of CuI-doped Bi2Te3 and undoped Bi2Te3. The addition of a small amount of Pb significantly decreased the carrier concentration, which could be attributed to the holes from Pb atoms, thus the CuI-Pb co-doped samples show a lower electrical conductivity and a higher Seebeck coefficient compared to CuI-doped samples with similar x values. The incorporation of Pb into CuI-doped Bi2Te3 rarely changed the power factor because of the trade-off relationship between the electrical conductivity and the Seebeck coefficient. The total thermal conductivity(&kappa;tot) of co-doped samples (&kappa;tot ~1.4 W/m∙K at 300 K) is slightly lower than that of 1% CuI-doped Bi2Te3 (&kappa;tot~1.5 W/m∙K at 300 K) and undoped Bi2Te3 (&kappa;tot ~1.6 W/m∙K at 300 K) due to the alloy scattering. The 1% CuI-Pb co-doped Bi2Te3 sample shows the highest ZT value of 0.96 at 370 K. All data on electrical and thermal transport properties suggest that the thermoelectric properties of Bi2Te3 and its operating temperature can be controlled by co-doping.

Lanthanide Based Ternary Intermetallics as Advanced Thermoelectric Materials

2006 ◽  
Vol 980 ◽  
Author(s):  
Ken Kurosaki ◽  
Takeyuki Sekimoto ◽  
Kenta Kawano ◽  
Hiroaki Muta ◽  
Shinsuke Yamanaka
Keyword(s):  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
High Temperatures ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Thermoelectric Materials ◽  
Room Temperature ◽  
Single Phase ◽  
Type Structure ◽  
Large Power

AbstractPolycrystalline ingots of the lanthanide based ternary intermetallics: LaNiSb, GdNiSb, ErNiSb and ErPdSb were prepared and characterized. The thermoelectric properties of ErNiSb and ErPdSb were measured at high temperatures. We succeeded in preparing the single phase ingots of ErNiSb and ErPdSb, while the ingots of LaNiSb and GdNiSb contain appreciable quantities of the impurity phases. ErNiSb and ErPdSb crystallize the MgAgAs-type structure (half-Heusler structure). ErNiSb and ErPdSb indicate positive values of the Seebeck coefficient. The values at room temperature are 36 and 240 micro VK-1 for ErNiSb and ErPdSb, respectively. The electrical resistivity of ErNiSb and ErPdSb decreases with temperature, indicating semiconductor-like behavior. ErPdSb exhibits a relatively large power factor 1.5x10-3 Wm-1K-2 at around 700 K, which is approximately two times larger than that of ErNiSb.

scholarly journals Фактор мощности твердых растворов на основе теллурида висмута в области топологических фазовых переходов при высоких давлениях

2019 ◽  
Vol 53 (6) ◽  
pp. 741
Author(s):  
И.В. Коробейников ◽  
Н.В. Морозова ◽  
Л.Н. Лукьянова ◽  
О.А. Усов ◽  
С.В. Овсянников
Keyword(s):  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Solid Solutions ◽  
Power Factor ◽  
Pressure Range ◽  
Room Temperature ◽  
Thermoelectric Module ◽  
Topological Phase ◽  
Maximum Increase ◽  
Topological Phase Transition

The Seebeck coefficient S and the electrical conductivity σ of solid solutions based on bismuth telluride with substitutions in Bi and Te sublattices were studied at pressures up to 12 GPa at room temperature. It is shown that with increasing pressure, the electrical conductivity increases and, despite the decrease in the Seebeck coefficient, an increase in the power factor (S^2)σ is observed in p-Bi0.5Sb1.5Te3 and n-Bi2Te1.65Se0.65S0.7 solid solutions. The maximum increase in the power factor was found for n-Bi2Te1.65Se0.65S0.7 in the pressure range of 3−4 GPa, corresponding to the electronic topological phase transition. The investigated solid solutions were used in the model of a thermoelectric module with adjustable mechanical stress applied to thermoelements.

Thermoelectric Properties of Zn-Sb Thin Films Grown by Ion Beam Sputtering

2012 ◽  
Vol 538-541 ◽  
pp. 154-157
Author(s):  
Peng Juan Liu ◽  
Ping Fan ◽  
Zhuang Hao Zheng ◽  
Dong Ping Zhang ◽  
Xing Min Cai ◽  
...  
Keyword(s):  
Thin Films ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Room Temperature ◽  
Ion Beam ◽  
Composition Analysis ◽  
Ion Beam Sputtering ◽  
Beam Sputtering ◽  
Sputter Deposited

Antimony (Sb) and zinc (Zn) bilayer was sputter-deposited at room temperature with various Zn contents by ion-beam sputtering and transformed into Antimony zinc after post thermal annealed at 573K for 60 min. A power factor of 6.18×10-4 W/mK2 at 473 K has been obtained when the sputtering time of the Zn was 20 minutes. The maximum Seebeck coefficient is 42.0 μVK-1. Composition analysis shows that the compound of SbZn is achieved and the small Seebeck coefficient is due to the deviation of stoichiometric.

scholarly journals Binary treatment of PEDOT:PSS films with nitric acid and imidazolium-based ionic liquids to improve the thermoelectric properties

2020 ◽  
Vol 1 (9) ◽  
pp. 3233-3242
Author(s):  
Temesgen Atnafu Yemata ◽  
Yun Zheng ◽  
Aung Ko Ko Kyaw ◽  
Xizu Wang ◽  
Jing Song ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Ionic Liquids ◽  
Nitric Acid ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Post Treatment

Binary post-treatment of thermoelectric PEDOT:PSS films with nitric acid and imidazolium-based ionic liquids significantly improves the electrical conductivity and Seebeck coefficient, leading to a power factor of 152 μW m−1 K−2.

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