Methods and Apparatus for Measuring Thermopower and Electrical Conductivity of Thermoelectric Materials at High Temperatures

Бурков, А. Т.; Федотов, А И; Новиков, С. В.

doi:10.5772/66290

Cited by 10 publications

(7 citation statements)

References 41 publications

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“…Figure 2 d exhibits the change in the resistance of the PCMO film in the HRS and LRS with respect to the measuring temperature. The resistance of the PCMO film in the HRS decreased with an increase in the temperature, indicating that this PCMO film has insulating properties [ 55 ]. These properties could be the result of the OV filaments possibly being disconnected during the reset process.…”

Section: Resultsmentioning

confidence: 99%

“…These properties could be the result of the OV filaments possibly being disconnected during the reset process. However, the resistance of the PCMO film in the LRS increased with increasing temperature, implying that, in the LRS, the PCMO film has metallic conducting properties [ 55 ]. This result implies that the conducting OV filaments were connected in the LRS, inducing metallic properties in the PCMO film.…”

Section: Resultsmentioning

confidence: 99%

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Effect of Oxygen Vacancy on the Conduction Modulation Linearity and Classification Accuracy of Pr0.7Ca0.3MnO3 Memristor

et al. 2021

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An amorphous Pr0.7Ca0.3MnO3 (PCMO) film was grown on a TiN/SiO2/Si (TiN–Si) substrate at 300 °C and at an oxygen pressure (OP) of 100 mTorr. This PCMO memristor showed typical bipolar switching characteristics, which were attributed to the generation and disruption of oxygen vacancy (OV) filaments. Fabrication of the PCMO memristor at a high OP resulted in nonlinear conduction modulation with the application of equivalent pulses. However, the memristor fabricated at a low OP of 100 mTorr exhibited linear conduction modulation. The linearity of this memristor improved because the growth and disruption of the OV filaments were mostly determined by the redox reaction of OV owing to the presence of numerous OVs in this PCMO film. Furthermore, simulation using a convolutional neural network revealed that this PCMO memristor has enhanced classification performance owing to its linear conduction modulation. This memristor also exhibited several biological synaptic characteristics, indicating that an amorphous PCMO thin film fabricated at a low OP would be a suitable candidate for artificial synapses.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Effect of Oxygen Vacancy on the Conduction Modulation Linearity and Classification Accuracy of Pr0.7Ca0.3MnO3 Memristor

et al. 2021

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“…The selected methods and models (5), ( 6) made it possible to implement the entire complex of studies on a sample of one configuration (Fig. 1), which significantly reduced the labor intensity and time for preparing the experiment in comparison with classical methods [1,9,10]. In addition, the described research methods and tools are non-destructive and do not require, for example, drilling a sample to determine thermal conductivity, as in the radial flow method.…”

Section: Discussion Of Research Resultsmentioning

confidence: 99%

“…Also, the problems of increasing the accuracy of sensors for measuring physical quantities at low temperatures are described by the authors of [8]. The authors of [9] described in sufficient detail the technique and means of high-temperature (1,000 K) thermoelectric measurements. Despite the simplicity of the measurement methods, their practical implementation is rather difficult, especially at high temperatures.…”

Section: Literature Review and Problem Statementmentioning

confidence: 99%

Features for the design of a specialized information-measuring system for the study of thermoelectric properties of semiconductors

Dunets

Dzundza

Turovska

et al. 2021

EEJET

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Methods for studying thermoelectric parameters of semiconductors that are optimal for the implementation of software and hardware have been analyzed and selected. It is based on the Harman method and its modifications, adapted for pulse measurements, which are convenient to implement on a modern element base. An important advantage of these methods is the absence of the need for accurate measurements of heat fluxes, which greatly simplifies and reduces the time for conducting experimental research. The required operating ranges for the voltage 10 µV–1 V, for the current 10 µA–300 mA and the element base performance at the processing level of 40–200 million samples per second have been determined. Structural and electrical circuits, as well as software for a specialized computer system for studying thermoelectric parameters of both bulk and thin-film thermoelectric materials, and express analysis of the operational characteristics of finished modules have been developed. It has been shown that the proposed scheme copes well with the task. And the use of FPGA and 32-bit microcontrollers provide sufficient processing speed up to 200 MSPS and the necessary synchronization modes for the implementation of the Harman pulse method even when studying films of nanometer thickness. Experimental studies of both bulk thermoelectric modules based on Bi2Te3 and thin-film thermoelectric material based on PbTe have been carried out. The effectiveness of the developed tools and techniques has been shown, which made it possible to more than halve the time for sample preparation and experiment. Based on the presented models, all the main thermoelectric and operational parameters have been determined, in particular, electrical conductivity, Seebeck coefficient, thermal conductivity, thermoelectric figure of merit. As a result of the development of specialized computer tools, it was possible to reduce the labor intensity of the process of measuring the main electrical and operational parameters of semiconductor thermoelectric materials and energy conversion modules based on them, as well as to automate the process of defects identification of thermoelectric modules. The labor intensity of the research process has decreased not only due to the automation of the measurement process, but also due to an optimized technique that allows research on a sample of one configuration, since the manufacture and preparation of samples are the most laborious

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“…However, the resistance of the Ag

CuS

samples was too high for simultaneous resistivity and Seebeck coefficient measurements. Therefore, using this setup only the thermal conductivity was measured at temperatures from 100 K to 600 K. The resistivity and Seebeck coefficients were measured with another setup with higher input impedance and therefore capable to measure samples with higher resistance [ 16 , 17 ]. The standard uncertainty of the thermal conductivity measurements is below ±10%.…”

Section: Sample Preparation and Characterisationmentioning

confidence: 99%

Band Structure, Phonon Spectrum and Thermoelectric Properties of Ag3CuS2

et al. 2023

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Sulfides and selenides of copper and silver have been intensively studied, particularly as potentially efficient thermoelectrics. Ag3CuS2 (jalpaite) is a related material. However very little is known about its physical properties. It has been found that the compound undergoes several structural phase transitions, having the tetrahedral structural modification I41/amd at room temperature. In this work, its band structure, phonon spectrum and thermoelectric properties were studied theoretically and experimentally. Seebeck coefficient, electrical conductivity and thermal conductivity were measured in a broad temperature range from room temperature to 600 K. These are the first experimental data on transport properties of jalpaite. Ab initio calculations of the band structure and Seebeck coefficient were carried out taking into account energy dependence of the relaxation time typical for the scattering of charge carriers by phonons. The results of the calculations qualitatively agree with the experiment and yield large values of the Seebeck coefficient characteristic for lightly doped semiconductor. The influence of intrinsic defects (vacancies) on the transport properties was studied. It was shown that the formation of silver vacancies is the most probable and leads to an increase of hole concentration. Using the temperature dependent effective potential method, the phonon spectrum and thermal conductivity at room temperature were calculated. The measurements yield low lattice thermal conductivity value of 0.5 W/(m K) at 300 K, which is associated with the complex crystal structure of the material. The calculated room temperature values of the lattice thermal conductivity were also small (0.14–0.2 W/(m K)).

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Methods and Apparatus for Measuring Thermopower and Electrical Conductivity of Thermoelectric Materials at High Temperatures

Cited by 10 publications

References 41 publications

Effect of Oxygen Vacancy on the Conduction Modulation Linearity and Classification Accuracy of Pr0.7Ca0.3MnO3 Memristor

Effect of Oxygen Vacancy on the Conduction Modulation Linearity and Classification Accuracy of Pr0.7Ca0.3MnO3 Memristor

Features for the design of a specialized information-measuring system for the study of thermoelectric properties of semiconductors

Band Structure, Phonon Spectrum and Thermoelectric Properties of Ag3CuS2

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