Vortex Express Method for Parameter Determination Thermoelectric Materials

The method is based on the possibility of determining the heat loss of electric power during the flow of Foucault eddy currents in the volume of a thermoelectric sample, placing in the field of action of the ferrite core an inductor through which electric currents that are symmetrical and asymmetric in nature flow sequentially in time. Mathematical expressions are obtained for the coefficients of electrical conductivity σ, thermal conductivity ϰ, thermo-emf α and thermoelectric figure of merit Z. Minimization of the error of the proposed method, carried out by computer simulation of the physical processes occurring in the sample using appropriate programs, showed that the operating frequency of the device measuring sensors should be located in the range of 36 ÷ 250 kHz, and the electric current flowing through it — taking into account the inequality qф/П/ qф/ qϰ > 10. The magnetic field induction ratio in terms of components is selected from the condition В0/В > 8.6, which corresponds to the conditions of minimal impact on the parameters of the sample by galvanic thermomagnetic phenomena. The block diagram of a device for non-contact measurement of symmetric σс and asymmetric σа components of the electrical conductivity of thermoelectric materials consists of: 1 — SV switch block; 2 — electronic switch; 3 — auto generator; 4 — AC amplifier; 5 — synchronous detector; 6 — DC amplifier; 7 — pulse generator; 8 — signal processing unit; 9 — indicator device; 10 — DC indicator; 11 — correction unit; FR1, FR2. Measurement of the parameters of the thermoelectric sample based on Bi-Te-Se-Sb crystals showed that the real error of the proposed method is 2 %. This indicates that the eddy current method can be successfully used to determine the main parameters of thermoelectric materials. The use of this method allows solving the relevant problem of avtomazation of the process of monitoring and sorting out thermoelectric ingots, billets and parts.

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Thermal spraying. Measurement of the electrical conductivity of thermal sprayed non-iron metal coatings by means of eddy current method

10.3403/30313327 ◽

2016 ◽

Keyword(s):

Electrical Conductivity ◽

Eddy Current ◽

Thermal Spraying ◽

Current Method ◽

Eddy Current Method ◽

Metal Coatings ◽

Iron Metal

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Investigation of Thermoelectric Materials: Substitution effect of Bi on the Ag1-xPb18MTe20 (M = Sb, Bi) (x = 0, 0.14, 0.3)

MRS Proceedings ◽

10.1557/proc-1044-u03-14 ◽

2007 ◽

Vol 1044 ◽

Author(s):

Mi-kyung Han ◽

Huijun Kong ◽

Ctirad Uher ◽

Mercouri G Kanatzidis

Keyword(s):

Thermal Conductivity ◽

Electrical Conductivity ◽

Seebeck Coefficient ◽

Thermoelectric Materials ◽

Figure Of Merit ◽

Lattice Thermal Conductivity ◽

Substitution Effect ◽

Dimensionless Figure Of Merit ◽

The Matrix ◽

Mass Fluctuation

AbstractWe performed comparative investigations of the Ag1-xPb18MTe20 (M = Bi, Sb) (x = 0, 0.14, 0.3) system to better understand the roles of Sb and Bi on the thermoelectric properties. In both systems, the electrical conductivity nearly keeps the same values, while the Seebeck coefficient decreases dramatically in going from Sb to Bi. Compared to the lattice thermal conductivity of PbTe, that of AgPb18BiTe20 is substantially reduced. The lattice thermal conductivity of the Bi analog, however, is higher than that of AgPb18SbTe20 and this is attributed largely to the decrease in the degree of mass fluctuation between the nanostructures and the matrix (for the Bi analog). As a result the dimensionless figure of merit ZT of Ag1-xPb18MTe20 (M = Bi) is found to be smaller than that of Ag1-xPb18MTe20 (M = Sb).

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Application of Eddy Currents in Processed Materials Structural Evaluation

Materials Science Forum ◽

10.4028/www.scientific.net/msf.730-732.715 ◽

2012 ◽

Vol 730-732 ◽

pp. 715-720

Author(s):

Telmo G. Santos ◽

João Faria ◽

Pedro Vilaça ◽

R.M. Miranda

Keyword(s):

Electrical Conductivity ◽

Solid State ◽

Eddy Currents ◽

Microstructural Analysis ◽

Structural Features ◽

Crystal Defects ◽

Electrical Currents ◽

Friction Stir ◽

Characterization Technique ◽

Physical Phenomena

Eddy currents are based on electromagnetic induction and analysis of electrical currents on conductive materials. This method is used for thickness measurements, corrosion and defects detection, electrical conductivity and magnetic permeability measurements. Recently, it has been exploited as a materials characterization technique, namely in solid state welding, since, compared to hardness, it is based in distinct physical phenomena. Electrical conductivity is controlled by electronic mobility, while hardness depends on crystal defects and thus a scale factor exists. This paper presents results of this characterization technique applied to multipass solid state friction stir processing (FSP) of AA1100 alloy. These results were compared to microstructural analysis and hardness measurements and show that eddy current is a feasibly, reliable and expedite technique to characterize processed materials. The electrical conductivity measured by eddy currents, maps more precisely structural features, while hardness does not. Measurement of electrical conductivity field suggests having potential to constitute an alternative and/or complement to hardness evaluation with the further advantage of being a non-destructive method.

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Температурные зависимости электропроводности и магнитной восприимчивости кристаллов твердых растворов Sb-=SUB=-2-=/SUB=-Te-=SUB=-3-=/SUB=--Bi-=SUB=-2-=/SUB=-Te-=SUB=-3-=/SUB=-

Физика и техника полупроводников ◽

10.21883/ftp.2021.12.51700.17 ◽

2021 ◽

Vol 55 (12) ◽

pp. 1162

Author(s):

Н.П. Степанов ◽

В.Ю. Наливкин ◽

А.К. Гильфанов ◽

А.А. Калашников ◽

Е.Н. Трубицына

Keyword(s):

Electrical Conductivity ◽

Magnetic Susceptibility ◽

Solid Solutions ◽

Thermoelectric Materials ◽

Materials Science ◽

Practical Importance ◽

Experimental Studies ◽

Electronic System ◽

Temperature Dependences ◽

The Subject

Solid solutions Bi2Te3-Sb2Te3 continue to be the subject of numerous and versatile experimental studies due to their practical importance for thermoelectric materials science. In this regard, the problem of studying the regularities of changes in the state of the electronic system of these semiconductors from composition and temperature remains urgent. This paper presents the results of studying the temperature dependences of the magnetic susceptibility of Bi2Te3-Sb2Te3 crystals containing 10, 25, 40, 50, 60 mol. % Sb2Te3. The correlation of the behavior of the temperature dependences of the magnetic susceptibility and electrical conductivity is analyzed.

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An Eddy-Current Method of Flaw Detection in Nonmagnetic Metals

Journal of Applied Mechanics ◽

10.1115/1.4009085 ◽

1941 ◽

Vol 8 (1) ◽

pp. A22-A26

Author(s):

Ross Gunn

Keyword(s):

Eddy Current ◽

Eddy Currents ◽

Flaw Detection ◽

Current Method ◽

Test Sample ◽

Current Pattern ◽

Eddy Current Method ◽

Recorded Performance ◽

Alternating Magnetic Fields ◽

Nonmagnetic Metals

Abstract An equipment suitable for the location of surface or submerged flaws in nonmagnetic metals is described. A predetermined pattern of electrical eddy currents is induced in a perfect test sample by alternating magnetic fields. Sensitive pickup coils properly disposed in relation to the eddy currents measure only the departures of the eddy-current pattern from the pattern in the perfect sample. The departures are indicated on a meter or may be recorded. Performance data are given for a universal type of search unit especially adapted for general surveys.

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Balancing the electrical conductivity and Seebeck coefficient by controlled interfacial doping towards high performance benzothienobenzothiophene-based organic thermoelectric materials

Journal of Materials Chemistry A ◽

10.1039/c9ta09620e ◽

2019 ◽

Vol 7 (43) ◽

pp. 24982-24991 ◽

Cited By ~ 7

Author(s):

Jingjuan Tan ◽

Zhanhua Chen ◽

Dagang Wang ◽

Shihui Qin ◽

Xu Xiao ◽

...

Keyword(s):

Electrical Conductivity ◽

Seebeck Coefficient ◽

Thermoelectric Materials ◽

High Performance ◽

Organic Thermoelectric Materials

A generally applicable strategy of balancing the electrical conductivity and Seebeck coefficient for high-performance organic thermoelectric composites by controlled interfacial doping.

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Simulation of Morphological Effects on Thermoelectric Power, Thermal and Electrical Conductivity in Multi‐Phase Thermoelectric Materials

Thermoelectrics for Power Generation - A Look at Trends in the Technology ◽

10.5772/65099 ◽

2016 ◽

Cited By ~ 2

Author(s):

Yaniv Gelbstein

Keyword(s):

Electrical Conductivity ◽

Thermoelectric Power ◽

Thermoelectric Materials ◽

Multi Phase

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Parameter determination of equivalent circuit for load effect due to ferrite core attachment

1999 International Symposium on Electromagnetic Compatibility (IEEE Cat. No.99EX147) ◽

10.1109/elmagc.1999.801406 ◽

2003 ◽

Author(s):

A.Z. Samir ◽

O. Fujiwara

Keyword(s):

Equivalent Circuit ◽

Parameter Determination ◽

Ferrite Core ◽

Load Effect

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Thermoelectric Performance of Glass Microsphere Dispersed Bi-Sb Composites at Low Temperature

Materials Science Forum ◽

10.4028/www.scientific.net/msf.743-744.120 ◽

2013 ◽

Vol 743-744 ◽

pp. 120-125

Author(s):

Zhen Chen ◽

Ye Mao Han ◽

Min Zhou ◽

Rong Jin Huang ◽

Yuan Zhou ◽

...

Keyword(s):

Thermal Conductivity ◽

Electrical Conductivity ◽

Seebeck Coefficient ◽

Thermoelectric Materials ◽

Sem Analysis ◽

Glass Microsphere ◽

Thermoelectric Performance ◽

X Ray Diffraction ◽

X Ray ◽

Measurement Results

In the present study, the glass microsphere dispersed Bi-Sb thermoelectric materials have been fabricated through mechanical alloying followed by pressureless sintering. The phase composition and the microstructure were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis. Electrical conductivity, Seebeck coefficient and thermal conductivity were measured in the temperature range of 77~300 K. The ZT values were calculated according to the measurement results. The results showed that the electrical conductivity, Seebeck coefficient and thermal conductivity decreased by adding glass microsphere into Bi-Sb thermoelectric materials. However, the optimum ZT value of 0.24 was obtained at 260 K, which was increased 10% than that of the Bi-Sb matrix. So it is confirmed that the thermoelectric performance of Bi-Sb-based materials can be improved by adding moderate glass microspheres.

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