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Showing papers on "Thermoelectric effect published in 1977"


Journal ArticleDOI
TL;DR: In this article, a series of a-Si specimens doped substitutionally with phosphorous were used for glow discharge decomposition of silane containing predetermined concentrations of phosphine, and the thermoelectric power of all the samples investigated was negative as expected.
Abstract: Thermoelectric power and conductivity measurements have been made as a function of temperature on a series of a-Si specimens doped substitutionally with phosphorous. The samples were prepared by the glow discharge decomposition of silane containing predetermined concentrations of phosphine. The thermoelectric power of all the samples investigated was negative as expected. For the lightly doped specimens the thermoelectric and conductivity results support the model developed from previous work. Electron transport is in the extended states, but below room temperature there is an increasing contribution from tail state hopping. At higher doping concentrations the data can be interpreted in terms of transport through the extended states and the localized donor states, as suggested by the analysis of recent Hall effect results. The value of the intercept S 0 on the S axis at 1/T = 0 depends strongly on the position of the Fermi energy ∊F with respect to the mobility edge at ∊c. The movement of ∊F with...

99 citations


Journal ArticleDOI
TL;DR: In this paper, the thermal conductivity and thermoelectric power of an inhomogeneous material subjected simultaneously to gradients of temperature and electric potential are accounted for in terms of an effective medium theory as well as by numerical simulations in cubic networks with correlated bonds.
Abstract: The thermal conductivity and thermoelectric power of an inhomogeneous material subjected simultaneously to gradients of temperature and electric potential are accounted for in terms of an effective-medium theory as well as by numerical simulations in cubic networks with correlated bonds.

85 citations


Journal ArticleDOI
TL;DR: In this article, the fast transient response of a thermoelectric (TE) cooler with novel geometry is discussed, which involves conical semiconductor legs whose hot to cold junction cross-sectional area ratios can be varied.

51 citations


Journal ArticleDOI
TL;DR: The thermal conductivity, electrical resistivity ρ, and Seebeck coefficient S of a high-purity Cr specimen (ρ273/ρ42=380) were measured from 285 to 1000 K as discussed by the authors.
Abstract: The thermal conductivity λ, electrical resistivity ρ, and Seebeck coefficient S of a high‐purity Cr specimen (ρ273/ρ42=380) were measured from 285 to 1000 K The ρ and S of two other Cr specimens (ρ273/ρ42=380 and 58) were determined from 300 to 1300 K The ρ and S results from the three specimens are in excellent agreement and all three properties agree to within experimental uncertainty with previous low‐temperature results on the same specimens over the temperature range of overlap Near T′ N (300–320 K), the present λ results are within 07% of the previous data and indicate that λρ/T should be smooth to within 1% At high temperature, the present λ data are about 8% above those of Powell and Tye but the ratios of λρ/T agree to within 2% up to 1000 K These new data on pure Cr are compared to calculations from standard transport theory and to previous results from W and Mo

51 citations



Journal ArticleDOI
TL;DR: In this article, general theoretical expressions of the thermoelectric power of metallic films were deduced from the Mayadas-Shatzkes conduction model of monocrystalline and polycrystalline films.

38 citations


Patent
Lecon Woo1
25 Feb 1977
TL;DR: In this article, a heat flow type differential calorimeter uses a planar thermoelectric disc as its major heat flow path for transferring heat to the sample and reference capsules.
Abstract: A heat flow type differential calorimeter uses a planar thermoelectric disc as its major heat flow path for transferring heat to the sample and reference capsules. To improve the reproducibility of the calorimeter, two small discs of a thermoelectric material capable of forming a thermocouple with the thermoelectric disc are attached thereto in face-to-face relationship. Next a thermocouple pair made of the same material as the small disc and a third material, capable of forming a thermocouple with the disc, is attached to the center of each of the small discs. This converts the usual point contact temperature sensor to a large surface area temperature sensor and hence improves the reproducibility of the thermal analyzer.

37 citations


Journal ArticleDOI
TL;DR: In this article, an electrical analog of the thermal model for the thermoelectric (TE) device is developed, which allows the researcher to predict the transient and steady state behavior of TE devices.

36 citations


Journal ArticleDOI
TL;DR: In this paper, the thermoelectric power has been measured on both sides of the melting point for Fe, Co and Ni in terms of the s-d scattering model proposed by Mott (1972).
Abstract: The thermoelectric power has been measured on both sides of the melting point for Fe, Co and Ni. The data for the liquid state are discussed in terms of the s-d scattering model proposed by Mott (1972).

34 citations


Journal ArticleDOI
TL;DR: In this article, the authors compared the temperature dependence of the threshold current density and the emission wavelength of double-heterostructure PbS-PbSe−PbS DH-laser with PbSe-homojunction DH-Laser with a germanium etalon for a quick evaluation of the spectral quality of emitted radiation.
Abstract: PbS−PbSe−PbS double-heterostructure lasers have been pulse-operated at about 200 K mounted on 4 stage thermoelectric coolers. Emitting at a wavelength of about 5.5 μm they could be used for NO gas spectroscopy. Operation temperatures of up to 230 K have been achieved with structures consisting ofn-type PbS substrates and epitaxial layers ofn-type PbSe and Tl dopedp-type PbS. The temperature dependence of the threshold current density and the emission wavelength of these DH-lasers was compared with PbSe-homojunction lasers. The use of a germanium etalon for a quick evaluation of the spectral quality of the emitted radiation is described.

30 citations



Journal ArticleDOI
TL;DR: In this paper, the thermoelectric power (TEP) of all the rare earth metals except promethium was measured in the temperature range 80 − 1000 K. The Hall constants R of gadolinium, terbium and dysprosium were also measured.
Abstract: The thermoelectric power (TEP) S was measured for all the rare earth metals except promethium, in the temperature range 80 – 1000 K. Data are also presented for scandium and yttrium. The available published data on the thermo power of the rare earths above 4.2 K are also presented. The TEP temperature dependences of almost all the rare earths were found to be similar. Measurements of the electrical resistivity ρ of almost all the metals were made in the same temperature range. The Hall constants R of gadolinium, terbium and dysprosium were also measured.

Journal ArticleDOI
TL;DR: In this paper, the authors used a solid electrolyte twin thermocell for the direct determination of the partial molar entropy of oxygen in a single-phase or multiphase mixture.

Journal ArticleDOI
TL;DR: In this paper, the authors measured the activation energies obtained from the temperature dependence of the thermoelectric power were smaller than those obtained from dc conductivity, and the discrepancy in the activation energy was successfully explained by assuming that the predominant carriers (holes) have thermally activated mobilities.
Abstract: Thermoelectric power and dc conductivity were measured as a function of temperature for Si–As–Te and Ge–As–Te glasses. The activation energies obtained from the temperature dependence of the thermoelectric power were smaller than those obtained from dc conductivity. This discrepancy in the activation energy was successfully explained by assuming that the predominant carriers (holes) have thermally-activated mobilities.

Journal ArticleDOI
TL;DR: In this paper, the Seebeck, Peltier and Thomson effects are described, in particular their use in measuring thermoelectric power, in relation to the use of real metals.
Abstract: The origin of thermoelectric effects occurring in metals is simply explained for the benefit of teachers. The Seebeck, Peltier and Thomson effects are described, in particular their use in measuring thermoelectric power. The theory of thermoelectric power is provided and in relation to the use of real metals. Thermocouple calibration is treated. Contact potentials and their effect on thermoelectric power are dealt with.

Patent
03 Oct 1977
TL;DR: A scanning radiometer has a series of laminations forming a tightly bonded sandwich structure each being electrically insulated from adjacent ones thereof, and in which the thermo responsive material is formed of a set of matrix of thin metal alternately with absorptive or blackened portions, each forming opposite arms of a Wheatstone bridge as mentioned in this paper.
Abstract: A scanning radiometer having a series of laminations forming a tightly bonded sandwich structure each being electrically insulated from adjacent ones thereof, said series including a thermometric or thermo responsive material, a heat pump functioning material, a heat sink functioning material, and an insulator functioning material, and in which the thermo responsive material is formed of a set of matrix of thin metal alternately with absorptive or blackened portions, each forming opposite arms of a Wheatstone bridge. The use of the term "thermoelectric or thermoresponsive material" designates a metallic or other electric resistor whose resistance is temperature sensitive and when measured, is an indicator of its temperature. "Heat pump functioning material" is a thermoelectric device that tranfers or "pumps" heat from one of its two surfaces to the other when an electric current is supplied to its terminals. In pumping heat out of the "heat sink functioning material" to the "thermoelectric or thermoresponsive material" or vice vera, it cools or warms the latter until its temperature becomes identical to the mean radiant temperature of the two Pi environment which wants to be measured. Once that is achieved, the heat pump functioning component ceases to pump heat, in either direction, because it receives no current or potential from the Wheatstone bridge formed by a blackened and a reflective thermometer, because the two thermometers read the same termperature when, and only when, their temperatures are equal to the temperature of the mean radiant two Pi environment, and they cancel when the bridge is balanced and its output, consequently, zero.

Journal ArticleDOI
TL;DR: In this paper, the junction of the crystal and melt acts as the hot limb of a thermocouple, and temperature variations similar to those found by other workers using thermocouples in convectively unstable melts were detected.

Journal ArticleDOI
TL;DR: In this paper, a simple oxidation technique was used to remove traces of iron dissolved in gold and in its homovalent alloys, which enabled an accurate determination of the low temperature thermoelectric power characteristic of the solutes copper and silver in gold.
Abstract: For pt.I see ibid., vol.4, p.256 (1974). Traces of iron dissolved in gold and in its homovalent alloys have been removed using a simple oxidation technique. This has enabled an accurate determination of the low temperature thermoelectric power characteristic of the solutes copper and silver in gold. Electron diffusion and phonon drag contributions are determined and discussed. The strongly positive diffusion thermoelectric powers of the alloys measured at low temperatures differ markedly from the apparent impurity effect determined from applying the Nordheim-Gorter rule to room temperature measurements of the alloys. Results for homovalent silver, copper and gold alloys are collected together.

Journal ArticleDOI
V. A. Semenyuk1
TL;DR: In this article, the problem of the limiting efficiency of thermoelectric cooling is considered in the general case when no limitations are imposed on the shape of the elements and their contact surfaces.
Abstract: The problem of the limiting efficiency of thermoelectric cooling is considered in the general case when no limitations are imposed on the shape of the thermoelectric elements and their contact surfaces.


Patent
Jr. Edward F. Hampl1
29 Aug 1977
TL;DR: Tungsten, molybdenum, and alloys thereof are useful as electrode members for thermoelectric legs made from chalcogenides of copper and/or silver as discussed by the authors.
Abstract: Tungsten, molybdenum, and alloys thereof are useful as electrode members for thermoelectric legs made from chalcogenides of copper and/or silver.

Journal ArticleDOI
TL;DR: In this paper, a single crystal graphite was irradiated with fast neutrons of a total dose of 3×10 16 nvt, and after subsequently annealed at 250°C and 1400°C.
Abstract: Thermoelectric and thermomagnetic properties have been investigated of a single crystal graphite irradiated with fast neutrons of a total dose of 3×10 16 nvt, and after subsequently annealed at 250°C and 1400°C. The Seebeck coefficients ( S ) of the post-irradiated as well as the 250°C-annealed crystals are wholly positive at temperatures ( T ) between 300 K and 4.2 K, while the characteristic phonon drag anomaly still survives in the S vs T diagram, consisting of positive and negative components located around 25 K and 40 K respectively. Annealing at 1400°C, whereby the radiation-induced vacancies have mostly been recovered, makes the S vs T curve not much different from that of the unirradiated graphite, except for the doublet structure of the phonon drag dip. The presence of a magnetic field enhances the thermoelectricity in positive and/or negative direction. The Nernst-Ettingshausen coefficient measured at 6 kOe is also accompanied by the phonon drag anomaly having the doublet structure.

Journal ArticleDOI
TL;DR: In this article, the electrical properties of 1000-Athick tantalum films rf sputtered in Ar-N2-O2 mixtures have been studied, showing that the α-tantalum phase observed at zero reactive gas flow rate also remains when the oxygen flow rate is increased until the transition to Ta2O5 is observed.
Abstract: The electrical properties of 1000‐A‐thick tantalum films rf sputtered in Ar–N2–O2 mixtures have been studied. The properties of these films can be related to film structure and composition. For nitrogen‐doped films, as shown by AES analysis, thermoelectric power (TEP) may be related to the nitrogen content in the range of values between 10 and 40 at. %; at higher nitrogen contents the Hall coefficient may be more usefully used; in any case TEP and Hall coefficient measurements give complementary informations on transport properties and can be used to evaluate the carrier contribution. The β‐tantalum phase observed at zero reactive‐gas flow rate also remains when the oxygen flow rate is increased until the transition to Ta2O5 is observed. Doubly ionized oxygen vacancies for oxygen‐doped films affect the transport properties, thereby giving a small dependence of the electrical parameters on the oxygen content. The AES analysis results for N2+O2 doped films show that, when oxygen is admitted to a system in w...

Patent
14 Feb 1977
TL;DR: In this article, a tuning compensation device is proposed to reduce post-tuning frequency drift in voltage controlled oscillators, comprising a thermoelectric element, such as a wafer of doped semiconductor material, in contact with the junction of a tuning element.
Abstract: A tuning compensation device to reduce post-tuning frequency drift in voltage controlled oscillators, comprising a thermoelectric element, such as a wafer of doped semiconductor material, in contact with the junction of a tuning element, such as a varactor diode, to produce a correction to the control voltage and thereby compensate for thermally induced frequency drift.

Journal ArticleDOI
TL;DR: In this paper, the thermoelectric power of annealed HgSe-crystals was investigated between 20 and 80 K in transverse magnetic fields up to 10 T. It was possible to describe the data quantitatively by using Obraztsov's formula and taking account of collision damping by introducing a Dingle factor.

ReportDOI
01 Apr 1977
TL;DR: In this paper, P-Type copper selenides for use with N-Type gadolinium-selenide alloys in radioisotope thermoelectric generators for spacecraft power supplies are reported.
Abstract: Thermoelectric properties of P-Type copper selenides for use with N-Type gadolinium-selenide alloys in radioisotope thermoelectric generators for spacecraft power supplies are reported. (WHK)

Journal ArticleDOI
TL;DR: In this article, electrical resistivity ϱ and thermoelectric ratio G on air annealed reference grade Pt samples from 4 K down to 40 mK reveal ultra-low temperature anomalies in both properties.

Patent
Andre Elie1
01 Jul 1977
TL;DR: In this paper, a method for epitaxial deposition of a semiconductor by electrical polarization of a liquid phase at constant temperature is described, where the polarization is applied in the direction of the cooling by the Peltier effect with a current density which is lower than the threshold which causes the growth and which lies near same.
Abstract: A method for the epitaxial deposition of a semiconductor by electrical polarization of a liquid phase at constant temperature. Outside the growth time the polarization is applied in the direction of the cooling by the Peltier effect with a current density which is lower than the threshold which causes the growth and which lies near same.


Patent
27 Oct 1977
TL;DR: In this paper, a thermoelectric battery is suspended on the end of a unit, the other end of which is attached via a heat conducting mass to the casing to reduce stress on the unit in the event of shock or acceleration applied to the case and spring fingers not normally in contact with the heat source or the unit are positioned to arrest the source if the assembly rocks more than a predetermined amount.
Abstract: In a thermoelectric battery the heat source is suspended on the end of a thermoelectric unit, the other end of which is attached via a heat conducting mass to the casing. A resilient mounting permits resilient rocking of the thermoelectric unit to reduce stress on the unit in the event of shock or acceleration applied to the casing and spring fingers not normally in contact with the heat source or the thermoelectric unit are positioned to arrest the heat source if the assembly rocks more than a predetermined amount.