Experimental conditions required for accurate measurements of electrical resistivity, thermal conductivity, and dimensionless figure of merit (ZT) using Harman and impedance spectroscopy methods

ABSTRACTThe transport properties of the partially filled CaxCo4-yNiySb12 skutterudite compounds have been investigated in the 300 – 800 K temperature range. We underline the positive influence of the Ni substitution on the electrical resistivity and thermopower while the thermal properties – thermal conductivity – remains almost unaffected. These results suggest again a beneficial effect of Ni atoms on the dimensionless figure of merit in CoSb3 based compounds.

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Thermoelectric properties of hole-doped Yb1-xPbxBaCo4O7+δ ceramics

International Journal of Modern Physics B ◽

10.1142/s0217979215500824 ◽

2015 ◽

Vol 29 (14) ◽

pp. 1550082 ◽

Cited By ~ 6

Author(s):

Yubo Chen ◽

Runxiang Ma ◽

Kunlun Wang ◽

Feng Gao ◽

Xing Hu ◽

...

Keyword(s):

Thermal Conductivity ◽

Electrical Resistivity ◽

Solid State ◽

Figure Of Merit ◽

Solid State Reaction Method ◽

Doping Content ◽

Reaction Method ◽

Dimensionless Figure Of Merit ◽

Ceramic Samples ◽

Pb Doping

The effects of Pb doping on the thermoelectric (TE) properties of Yb 1-x Pb x BaCo4O7+δ (x = 0, 0.02, 0.04, 0.06, 0.08 and 0.1) ceramic samples prepared by the solid-state reaction method were investigated from 383 K to 973 K. The results showed that with increase of the Pb content, the electrical resistivity decreased remarkably, meanwhile the Seebeck coefficient decreased slightly, resulting in an enhancement of the power factor (PF). The effect of Pb doping on the thermal conductivity was insignificant. According to the PF and the dimensionless figure of merit (ZT) value, the optimum Pb doping content was x = 0.08. The ZT value reached 0.12 at 973 K, being 69.5% higher than that of the sample without Pb doping.

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Thermoelectric Properties of La-doped BaSi2 and (Ba,Sr)Si2 Solid Solutions

MRS Proceedings ◽

10.1557/proc-1044-u06-12 ◽

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.

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Thermoelectric properties of the Al-TM-Si (TM = Mn, Re) 1/1-cubic approximant

MRS Proceedings ◽

10.1557/proc-805-ll3.3 ◽

2003 ◽

Vol 805 ◽

Cited By ~ 1

Author(s):

Tsunehiro Takeuchi ◽

Toshio Otagiri ◽

Hiroki Sakagami ◽

Uichiro Mizutani

Keyword(s):

Thermal Conductivity ◽

Electrical Resistivity ◽

Thermoelectric Power ◽

Thermoelectric Properties ◽

Figure Of Merit ◽

Room Temperature ◽

Low Thermal Conductivity ◽

Dimensionless Figure Of Merit

ABSTRACTThe electrical resistivity, thermoelectric power, and thermal conductivity were investigated for the Al71.6-xMn 17.4Six and Al71.6-xRe 17.4Six (7 ≤ x ≤ 12) 1/1-cubic approximants. A large thermoelectric power ranging from -40 to 90 μV/K and a low thermal conductivity less than 3 W/K·cm were observed at room temperatures. The electrical resistivity at room temperature for these approximants was kept below 4,000 μΩcm, that is much smaller than that in the corresponding quasicrystals. As a result of the large thermoelectric power, the low thermal conductivity, and the low electrical resistivity, large dimensionless figure of merit ZT = 0.10 (n-type) and 0.07 (p-type) were achieved for the Al71.6Re17.4Si11 and Al71.6Mn17.4Si11 at room temperature, respectively.

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The thermoelectric properties of CoSb3 compound doped with Te and Sn synthesized at different pressure

Modern Physics Letters B ◽

10.1142/s021798491750261x ◽

2017 ◽

Vol 31 (28) ◽

pp. 1750261 ◽

Cited By ~ 2

Author(s):

Yiping Jiang ◽

Xiaopeng Jia ◽

Hongan Ma

Keyword(s):

Thermal Conductivity ◽

High Pressure ◽

Electrical Resistivity ◽

High Temperature ◽

Seebeck Coefficient ◽

Thermoelectric Properties ◽

Figure Of Merit ◽

Raw Materials ◽

Absolute Value ◽

Dimensionless Figure Of Merit

The skutterudite CoSb[Formula: see text]Te[Formula: see text]Sn[Formula: see text] compound was synthesized successfully by high pressure and high temperature (HPHT) method using Co, Sb, Te and Sn powder as raw materials. The effects of pressure on its structure and the thermoelectric properties are investigated systematically from 300 K to 800 K. The electrical resistivity and the absolute value of the Seebeck coefficient for the sample increases with rising synthetic pressure. The thermal conductivity of the sample decreases with synthetic pressure and temperature rising in the range of 300–800 K. In this study, the maximum dimensionless figure of merit (ZT) value of 1.17 has been achieved at 793 K, 3 GPa for this thermoelectric material.

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FEM Analysis on Thermoelectric Properties of Metal/TiO2–x Composites with Random Distribution of Metal Powder

Materials Science Forum ◽

10.4028/www.scientific.net/msf.750.130 ◽

2013 ◽

Vol 750 ◽

pp. 130-133

Author(s):

Katsuhiro Sagara ◽

Yun Lu ◽

Dao Cheng Luan

Keyword(s):

Thermal Conductivity ◽

Electrical Resistivity ◽

Seebeck Coefficient ◽

Thermoelectric Properties ◽

Power Factor ◽

Figure Of Merit ◽

Random Distribution ◽

The Other ◽

Dimensionless Figure Of Merit ◽

Wide Range

Analysis model of finite element method with a random distribution for thermoelectric composites was built. Thermoelectric properties including electrical resistivity, Seebeck coefficient and thermal conductivity of M/TiO2–x (M = Cu, Ni, 304 stainless steel (304SS)) thermoelectric composites were investigated by the proposed model. Cu/TiO2–x composite showed a large decrease in electrical resistivity while 304SS/TiO2–x composite thermal conductivity was slightly increased. Calculated dimensionless figure-of-merit, ZT of Ni/TiO2–x composite was higher than those of TiO2–x and the other composites in a wide range of metal volume fractions because Ni has large absolute values of Seebeck coefficient, power factor and dimensionless figure-of-merit compared to the other two metals. It was found that power factor and dimensionless figure-of-merit of thermoelectric composites depended on the balance among electrical resistivity, thermal conductivity and Seebeck coefficient. The results revealed that it is important for M/TiO2–x composites to choose suitable addition metal with high power factor and dimensionless figure-of-merit.

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Reduced Thermal Conductivity in ZrNiSn-Based Heusler Alloys

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.737.110 ◽

2015 ◽

Vol 737 ◽

pp. 110-113

Author(s):

Hong Yue Wei ◽

De Xuan Huo ◽

Wei Feng Yang ◽

Jin Wei Li ◽

Yin Jing Zhang

Keyword(s):

Thermal Conductivity ◽

Electrical Resistivity ◽

Figure Of Merit ◽

Heusler Alloys ◽

Drastic Reduction ◽

Arc Melting ◽

Dimensionless Figure Of Merit ◽

Plasma Sintering ◽

Spark Plasma ◽

Dual Site

Dual-site doped half-Heusler ZrNiSn alloys were prepared by arc melting. In order to diminish thermal conductivity of the alloys, as-casted ingots were sintered again by spark plasma sintering (SPS) technique after pulverizing and milling for several different periods of time. The electrical resistivity, thermoelectric powers and thermal conductivity of the sintered samples were measured from 4 to 350 K. A drastic reduction of thermal conductivity was obtained. The thermal conductivity decreased from about 17 to 1.5 W/K m and from 8.8 to 6.3 W/K m at 30 and 350 K, respectively. The dimensionless figure of merit of the half-Heusler alloys increased about 10%

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Bipolar doping and thermoelectric properties of Zintl arsenide Eu5In2As6

10.26434/chemrxiv-2021-9kq0r ◽

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.

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Thermoelectric Properties of Tl-X-Te (X=Pb, Sn, Ge) Systems

MRS Proceedings ◽

10.1557/proc-0886-f09-06 ◽

2005 ◽

Vol 886 ◽

Author(s):

Atsuko Kosuga ◽

Ken Kurosaki ◽

Hiroaki Muta ◽

Shinsuke Yamanaka

Keyword(s):

Thermal Conductivity ◽

Electrical Resistivity ◽

Solid State ◽

Electrical Properties ◽

Seebeck Coefficient ◽

Thermoelectric Properties ◽

Figure Of Merit ◽

Room Temperature ◽

Lattice Thermal Conductivity ◽

Dimensionless Figure Of Merit

ABSTRACTPolycrystalline-sintered samples of Tl2GeTe3, Tl4SnTe3, and Tl4PbTe3 were prepared by a solid-state reaction. Their thermoelectric properties were evaluated at temperatures ranging from room temperature to ca. 700 K by using the measured electrical resistivity (ρ), Seebeck coefficient (S), and thermal conductivity (κ). Despite their poor electrical properties, the dimensionless figure of merit ZT of all the compounds was relatively high, i.e., 0.74 at 673 K for Tl4SnTe3, 0.71 at 673 K for Tl4PbTe3, 0.29 at 473 K for Tl2GeTe3, due to the very low lattice thermal conductivity of the compounds.

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