Thermoelectric effect,

Seebeck s outstanding scientific achievement was the discovei"y of one of the three classical thermoelectric effects, which are the Seebeck, the Peltier, and the Thomson effects. Seebeck s discovery was the first, dating from 1822—1823, followed by that of Jean-Charles-Athanase Peltier in 1832 and that of William Thomson in 1854. Seebeck obseiwed that an electric current in a closed circuit comprised different metallic components if he heated the junctions of the components to different temperatures. He noted that the effect increases linearly with the applied temperature difference and that it crucially depends on the choice of materials. Seebeck tested most of the available metallic materials for thermoelectricity. His studies were further systematized by the French physicist... 

The Entropy Principle gives, on the assumptions as to reversibility of thermoelectric effects ... 

Thermoelectric effect discovered by T.J. Seebeck The Seebeck effect is the basis for the thermometers designated as thermocouples... 

Early bolometers used, as thermometers, thermopiles, based on the thermoelectric effect (see Section 9.4) or Golay cells in which the heat absorbed in a thin metal film is transferred to a small volume of gas the resulting pressure increase moves a mirror in an optical amplifier. A historical review of the development of radiation detectors until 1994 can be found in ref. [59,60], The modern history of infrared bolometers starts with the introduction of the carbon resistor, as both bolometer sensor and absorber, by Boyle and Rogers [12], The device had a number of advantages over the Golay cell such as low cost, simplicity and relatively low heat capacity at low temperatures. 

Roland W. Ure, Jr., Thermoelectric Effects in III-V Compounds Herbert Piller, Faraday Rotation... 

Figure 2 Configuration of reservoirs of energy and electrons used in the Onsager treatment of thermoelectric effects in wire A.

Uses. Low melting solders, low melting alloys and metallurgical additives. Bismuth is a metal with some unusual properties like Ge and Ga its volume increases in solidification. It is the most diamagnetic metal, its alloys show large thermoelectric effect with the exception of Be has the lowest absorption cross-section for thermal neutrons. 

Anomalous Thermoelectric Effect in the Shock Regime and Application to a Shock Pressure". Title of the paper by J. Crosnier et al in 4thONRSympDeton (1965), 627-38... 

Detonation, Shock Regime Thermoelectric Effect in. When a shock wave crosses the junction surface of two different metals, there appears between the uncompressed extremities of the metals a difference in potential, the magnitude of which is dependent on the amplitude of the shock wave the nature of the metals. This effect had been first noted in 1959 during the investigation of a thermal elec detector for the recording of temp at the shock front. 

Metal Oxide-Polymer Thermistors. The variation of electrical properties with temperature heretofore described can be used to tremendous advantage. These so-called thermoelectric effects are commonly used in the operation of electronic temperature measuring devices such as thermocouples, thermistors, and resistance-temperature detectors (RTDs). A thermocouple consists of two dissimilar metals joined at one end. As one end of the thermocouple is heated or cooled, electrons diffuse toward... 

The thermoelectric effect is due to the gradient in electrochemical potential caused by a temperature gradient in a conducting material. The Seebeck coefficient a is the constant of proportionality between the voltage and the temperature gradient which causes it when there is no current flow, and is defined as (A F/A7) as AT- 0 where A Fis the thermo-emf caused by the temperature gradient AT it is related to the entropy transported per charge carrier (a = — S /e). The Peltier coefficient n is the proportionality constant between the heat flux transported by electrons and the current density a and n are related as a = Tr/T. 

Like other organic compounds, dyes can be divided into n- and -type conductors. This may be confirmed by measuring the influence of oxygen or hydrogen ,14,84)> the Hall effect si,34,85) or the thermoelectric effect 66,86). Moreover, in agreement... 

Table 12 shows the quality factors or thermoelectric effectivities Gt... 

Detonation, shock regime thermoelectric effect in 4D520... 

A second historical line which, is of paramount importance to the present understanding of solid state processes is concerned with electronic particles (defects) rather than with atomic particles (defects). Let us therefore sketch briefly the, history of semiconductors [see H. J, Welker (1979)]. Although, the term semiconductor was coined in 1911 [J. KOnigsberger, J, Weiss (1911)], the thermoelectric effect had already been discovered almost one century earlier [T. J. Seebeck (1822)], It was found that PbS and ZnSb exhibited temperature-dependent thermopowers, and from todays state of knowledge use had been made of n-type and p-type semiconductors. Faraday and Hittorf found negative temperature coefficients for the electrical conductivities of AgzS and Se. In 1873, the decrease in the resistance of Se when irradiated by visible light was reported [W. Smith (1873) L. Sale (1873)]. It was also... 

This means that studies of the conductivity alone are insufficient to obtain a complete understanding of the mechanism of charge transfer. Other techniques such as photoconductivity, thermoelectric effect and mobility measurements are required for a deeper understanding of the phenomenon. 

Traditionally, charge transfer mechanisms have been studied by such methods as conductivity, the Hall effect, and thermoelectric effect. Details of these applications may be found in Experimental Methods of Physics, Vol. 6, Pt. b (12), the article on ionic conductivity by Lidiard (70), and in many of the original papers quoted. More recently, techniques such as electron spin resonance (13), dielectric loss and pulsed photoconductivity methods (5—8) have been used to study semiconduction in organic materials. 

Thermojunctions may be formed by welding, soldering or pressing the materials together. Such junctions give identical emfs (by law (iii)), but may well produce different currents as the contact resistance will differ depending on the joining process utilised. Whilst many materials exhibit thermoelectric effects, only a small number are employed in practice. The characteristics of the more common thermocouple materials are listed in Table 6.4. 

The electrical transport properties of alkali metals dissolved in ammonia and primary amines in many ways resemble the properties of simple electrolytes except that the anionic species is apparently the solvated electron. The electrical conductance, the transference number, the temperature coefficient of conductance, and the thermoelectric effect all reflect the presence of the solvated electron species. Whenever possible the detailed nature of the interactions of the solvated electrons with solvent and solute species is interpreted by mass action expressions. 

The anionic species is responsible for the anomalously large conductance and thermoelectric effects, and is definitely some form of solvated electron. 

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