Showing papers on "Thermoelectric effect published in 1970"
TL;DR: In this article, the authors investigated the thermoelectric power behavior of tungsten trioxide in the presence of oxygen deficiency and showed that the defect unit is not the oxygen vacancy but the Anderson-Hyde disk of shear.
240 citations
TL;DR: In this article, the authors used the hopping model and small polaron theory to understand the mechanism of conduction in rare earth sesquioxides and nonstoichiometric oxides of rare-earths.
97 citations
Patent•
31 Aug 1970
TL;DR: In this article, a Peltier effect pile is mounted in a heat exchanger or heat sink with semiconductive barrier layers insulating the peltier electrodes from the metal of the heat sink.
Abstract: A Peltier-effect pile is mounted in a heat exchanger or heat sink with semiconductive barrier layers insulating the Peltier electrodes from the metal of the heat sink. The semiconductive layers are poled electrically or biased to minimize electrical conductivity thereacross but permit maximum heat flow between the Peltier pile and the heat exchange jacket.
80 citations
TL;DR: In this paper, the Mott model for s-d scattering was used to calculate the electrical resistivity, thermal conductivity, and thermoelectric power at high temperatures for palladium, platinum, rhodium, iridium, molybdenum, and tungsten, by making use of the density of states determined in the rigid band model from the data of low temperature specific heat coefficients.
Abstract: In the Mott model for s - d scattering, the electrical resistivity, thermal conductivity, and thermoelectric power are calculated at high temperatures for palladium, platinum, rhodium, iridium, molybdenum, and tungsten, by assuming proper electronic structures, and making use of the density of states determined in the rigid band model from the data of low temperature specific heat coefficients. The results are compared with experiments. The calculated temperature dependences of electrical resistivity, thermal conductivity, and thermoelectric power at high temperatures are found to be strongly dependent on the shape of the density of states and the position of the Fermi level. All of these temperature dependences are consistent with the experimental results. It is confirmed that there is a strong correlation between these temperature dependences and those of electronic specific heat coefficient and spin susceptibility.
58 citations
TL;DR: In this paper, experimental values of the thermal conductivity and thermoelectric power of n-type silicon doped with phosphorus, antimony or arsenic, containing 4*1019 to 6*1025 m-3 electrons at room temperature, covering the range 4-300 degrees K.
Abstract: Experimental values are given of the thermal conductivity and thermoelectric power of n-type silicon doped with phosphorus, antimony or arsenic, containing 4*1019 to 6*1025 m-3 electrons at room temperature, covering the range 4-300 degrees K. A theoretical treatment, using the variational method, suggests that the ratio of phonon drag component of thermoelectric power to thermal conductivity should be independent of carrier concentration, if the latter is not too large. This is verified experimentally; the temperature variation of the ratio is in satisfactory agreement with theory, which also gives the correct order of magnitude for the absolute value.
58 citations
TL;DR: In this article, the authors consider simple variations of a basic resistive network model for an inhomogeneous material and show that a wide variety of experimentally observed effects can be described with respect to equilibrium or steady-state Hall and thermoelectric measurements.
Abstract: Consideration of simple variations of a basic resistive‐network model for an inhomogeneous material shows that a wide variety of experimentally observed effects can be described with respect to equilibrium or steady‐state Hall and thermoelectric measurements. The correlation between these macroscopic Hall and thermoelectric measurements and the microscopic electrical and geometrical properties of the material is derived. A suitable combination of both Hall and thermoelectric measurements on the same sample makes it possible to determine the dominant average microscopic and geometric parameters of the system. Although developed under the stimulus of research into the photoconductivity mechanism in chemically deposited lead sulfide layers, the results of the consideration may have a wider application.
53 citations
TL;DR: In this article, a 2-energy-level model is proposed for the Fe2+ ions, which removes most, though not all, discrepancies between predicted and experimental results, and shows a transition from a temperature independent region to a temperature activated region.
Abstract: Measurements are reported of the resistivity and the thermoelectric power as a function of temperature for nickel-iron ferrites. The thermoelectric power shows a transition from a temperature independent to a temperature activated region. The results are broadly in agreement with the Jonker hopping model but some disagreement with the accepted simple theory is found. A 2-energy-level model is proposed for the Fe2+ ions; this removes most, though not all, discrepancies between predicted and experimental results.
45 citations
TL;DR: In this paper, the thermal conductivity, thermoelectric power and electrical resistivity for a series of 20 annealed polycrystalline Ag-Au alloys, covering the whole 100% α-solid solution range of the system, have been measured from 3° to 300°k.
Abstract: The thermal conductivity, thermoelectric power and electrical resistivity for a series of 20 annealed polycrystalline Ag—Au alloys, covering the whole 100% α-solid solution range of the system, have been measured from 3° to 300°k. The thermoelectric power has been separated into diffusion and phonon drag components and the effect of Fe impurities has been taken into account. The attenuation of the phonon drag peak on alloying cannot be explained simply by the corresponding attenuation of the lattice component of the thermal conductivity, nor does it show the resurgence at high solute concentrations previously observed in other noble metal alloy systems.
45 citations
TL;DR: In this article, the ability of thermoelectric power measurements to permit a description of carrier density and phonon-drag variations caused by photoexcitation was tested in 100−Ω·cm n and p-type silicon.
Abstract: The ability of thermoelectric power measurements to permit a description of carrier‐density and phonon‐drag variations caused by photoexcitation was tested in 100‐Ω·cm n‐ and p‐type silicon. At low temperatures the major effect of photexcitation is to decrease the phonon‐drag contribution to the thermoelectric power by increasing the phonon density in the crystal. At higher temperatures the thermoelectric effect can be used to investigate changes in the electronic contribution due to photoexcitation. An apparently anomalous increase in thermoelectric power with photoexcitation was consistently found in p‐type silicon over an intermediate temperature range.
41 citations
TL;DR: In this article, the slopes of logρ and α vs. 1 T are quite different which can be explained by a hole mobility increasing exponentially with temperature, and the small polaron character of the holes is connected with Jahn-Teller deformations caused by the holes.
39 citations
TL;DR: In this article, the electrical resistivity p ancl the Seebeck coefficient S at temperatures up to 850°c in the range in which the two liquid phases are mutually soluble in orcler to study the transition between metallic and semiconductor behaviour.
Abstract: In the composition range 70 to 100 atomic % thallium, the phase diagram of Tl[sbnd]Te has a region with two immiscible phases below 600°c, corresponding to the separation of a metallic and a liquid semiconductor phase. We have made measurements of the electrical resistivity p ancl the Seebeck coefficient S at temperatures up to 850°c in the range in which the two liquid phases are mutually soluble in orcler to study the transition between metallic and semiconductor behaviour. As the concentration of tellurium is increased, p and the magnitude of S increase, and their temperature coefficients change from weakly positive values typical of metals to weakly negative values typical of liquid semiconductors with low resistivity. We find that the transport behaviour can be accounted for very well by a model which treats the alloy as a solution containing Tl2Te molecules plus metallic TI atoms. As Te is added to Tl2 electrons are removed from the conduction band, and scattering centres due to Tl2Te are a...
TL;DR: In this article, the switching phenomena in chalcogenide glasses have been analyzed as a thermoelectric effect and computer calculations relating current, voltage, temperature, and time have been made.
Abstract: Switching phenomena in chalcogenide glasses have been analysed as a thermoelectric effect. Computer calculations relating current, voltage, temperature, and time have been made. The results show a very fast switching but a slower cut-off. The temperature of the diode changes abruptly on switching. The calculated holding voltage in the conducting state is found to be nearly constant and independent of the ambient temperature. The main features of the results agree with the experimental data.
Patent•
21 Dec 1970
TL;DR: In this paper, a thermoelectric diffusion still including a concentric series of sections which sections are closely spaced to define annular diffusion spaces therebetween is described, and means are provided for collecting condensate from the opposite surface of each of the sections.
Abstract: A thermoelectric diffusion still including a concentric series of sections which sections are closely spaced to define annular diffusion spaces therebetween. A series of thermoelectric elements are positioned within such sections providing heated and cooled surfaces, respectively, on opposite sides of the section as well as facing each other across the spaces to evaporate and condense a feed fluid. Means are provided for collecting condensate from the opposite surface of each of the sections.
Patent•
28 May 1970
TL;DR: A plurality of alternating junctions of two types arranged in a series configuration is considered in this paper. But the effect is the cumulative Peltier effects produced at the first type of junction.
Abstract: A plurality of alternating junctions of two types arranged in a series configuration. The first junction type is comprised of two materials in overlapping arrangement. The second junction type is also comprised of two materials and additionally has a third material therebetween. Current flow through the junction produces a Peltier heating or cooling effect at the first type of junction. Either no thermal effect or both Peltier heating and cooling occur at the second type of junction which cancel out. The effect is the cumulative Peltier effects produced at the first type of junction.
TL;DR: In this article, the electrical resistivity and the thermoelectric power measurement on V 8 O 15 single crystals have been used to confirm the metal-to-semiconductor phase transition at 70 °K.
TL;DR: In this article, a comparison between He II when the normal fluid is clamped and the superconducting state of metals leads to an extension of the two-fluid equations of London.
Abstract: A comparison between He II when the normal fluid is clamped and the superconducting state of metals leads to an extension of the two-fluid equations of London. The following consequences are discussed: (a) A nonstationary thermal emf (thermal electric effect) can exist in a superconductor, (b) a stationary potential difference (not an emf) can exist.
TL;DR: In this article, the thermoelectric power of stabilized zirconia, at different CaO and MgO concentrations within the cubic phase, has been measured, and the results show a concentration dependence of the temperature which is preliminarly discussed.
Abstract: Abstract Thermoelectric power of stabilized zirconia, at different CaO and MgO concentrations within the cubic phase, has been measured. The results show a concentration dependence of the thermoelectric power which is preliminarly discussed. The homogeneous part of the thermoelectric power, moreover, is discussed with the classical approach of irreversible thermodynamics.
01 Jan 1970
01 Jan 1970
TL;DR: The first investigations of the thermoelectric properties of lead chalcogenides were carried out by Ioffe, Maslakovets et al. as mentioned in this paper.
Abstract: The first investigations of the thermoelectric properties of lead chalcogenides were carried out by Ioffe, Maslakovets et al. [207, 488–490]. The outcome of these investigations was the use of lead sulfide in the first thermoelectric generators and of lead telluride in various cooling units [490, 491]. Later it was found that alloys based on antimony and bismuth tellurides were more suitable materials for cooling purposes. Lead chalcogenides, particularly lead telluride and its alloys, were found to be the most efficient materials for thermoelectric generators working between room temperature and 600–650°C.
TL;DR: In this paper, four compounds of the general composition 12 2 36 4 have been studied to ascertain their thermoelectric properties and the results indicated that the bandgap in these semiconductors is less than 0.5 eV.
TL;DR: In this article, it was shown that when the two adjacent n and p arms of a thermocouple Peltier junction are shunted by a heavy silver film, an infinite cascade of differential cold and hot junctions is developed which effectively counteracts the flow of heat from the hot to the cold junction.
Abstract: It is shown that when the two adjacent n and p arms of a thermocouple Peltier junction are shunted by a heavy silver film an 'infinite cascade' of differential cold and hot junctions is developed which effectively counteracts the flow of heat from the hot to the cold junction When the thermal load on the cold junction is negligible, an improvement by a factor of between 15 and 3 has been obtained for the maximum temperature difference Delta Tmax over that attainable without the film It is further shown that for this arrangement, in which there are conducting paths transverse to the lengths of the arms, the conventional formulae for the calculation of the maximum attainable temperature difference from the figure of merit of the thermoelectric substances requires modification In addition to its thermodynamic interest, the method also appears to be of practical importance
TL;DR: The absolute thermoelectric powers of liquid alloys as a function of temperature and composition were reported in this article for fifteen Bi-, Cd-, In-, Pb- and Sn-base systems.
Abstract: The absolute thermoelectric powers of liquid alloys as a function of temperature and composition are reported for fifteen Bi-, Cd-, In-, Pb- and Sn-base systems.
Patent•
09 Feb 1970
TL;DR: In this article, a thermoelectric calorimeter for measuring microwave power in the watt range, using a thin-film resistive load, maintains the temperature balance of the thermal junctions by means of an aluminum oxide substrate on which the thermocorimeter films are deposited.
Abstract: A thermoelectric calorimeter for measuring microwave power in the watt range, and using a thin-film resistive load, maintains the temperature balance of the thermoelectric junctions by means of an aluminum oxide substrate on which the thermoelectric films are deposited. The substrate is effective for conducting the high level of heat energy produced with absorption of input power by the load to a heat sink (which is also used as the outer conductor of a waveguide that transmits the power to the load) and to a finned housing that receives the heat by conduction from the heat sink and is effective for transferring the heat energy to the ambient air by convection. The thin films of the load face frontwards in the unit and an electrical insulation having a low thermal resistance is provided.
TL;DR: In this paper, the Seebeck coefficient, thermal conductivity and electrical conductivity of Bi95Sb5 doped with various amounts of Te have been measured at 80 K, using samples that were oriented so as to yield the highest thermoelectric figure of merit.
Abstract: The Seebeck coefficient, thermal conductivity and electrical conductivity of crystals of Bi95Sb5 doped with various amounts of Te have been measured at 80 K, using samples that were oriented so as to yield the highest thermoelectric figure of merit. A dimensionless figure of merit of 058 has been observed for a crystal doped with nominally 0002 at.% Te in a magnetic field of 04 T, this being significantly higher than the best value that was found for an intrinsic crystal. From the change of thermal conductivity with magnetic field it has been possible to estimate a value of 2.8 W m−1 K−1 for the lattice conductivity. A rather low Lorenz number is attributed to inelastic scattering of the electrons.
TL;DR: In this paper, the conduction and thermoelectric powers of thiourea have been reported and the mobility of the charge carriers appears to be somewhat low, and Trapping of majority carriers is suggested to be responsible for the observed abnormalities.
Abstract: As part of an extensive programme on semiconduction in aliphatic molecular crystals, the conduction and thermoelectric powers of thiourea have been reported. Thiourea is found to be a p-type electronic semiconductor, has a very high value of Seebeck coefficient and has a high energy of activation for carrier generation (2.70 ev). The mobility of the charge carriers appears to be somewhat low. The results have been discussed on the basis of the model proposed by Johnson and Lark-Horowitz. Trapping of majority carriers is suggested to be responsible for the observed abnormalities.