Showing papers on "Seebeck coefficient published in 1976"
Book•
01 Oct 1976
TL;DR: Seebeck, Peltier, and Thomson as discussed by the authors described the Seebeck effect and the Thomson effect on the absolute thermoelectric power of lead and lead-lead, respectively.
Abstract: 1 Introduction- 11 Seebeck, Peltier, and Thomson Effects- 12 Transport Coefficients and Onsager Relations- 2 Survey of the Theory of Electronic Conduction in Metals- 21 Electrons in Metals- 21a Free Electron Gas- 21b Energy Bands- 22 Transport Properties- 23 Relaxation Time Anisotropy for Spherical Fermi Surfaces- 24 Thermopower: Isotropic Relaxation Time Approximation- 25 Thermopower: Real Metals- 25a Alkali and Noble Metals- 25b Polyvalent Metals- 26 Phonon Drag- 27 Thermopower of Alloys- 27a Diffusion Thermopower- 27b Phonon Drag- 3 Techniques in Thermoelectric Measurements- 31 Introduction- 32 Seebeck Effect- 33 Peltier Effect- 34 Thomson Effect: The Absolute Thermopower of Lead- 35 Measurement of Unconventional Thermoelectric Coefficients- 36 Measurement of Temperature and of Small Voltages- 36a Temperature Measurement- 36b Voltage Measurement- 37 Superconducting Devices- 37a Superconducting Modulators- 37b Weak Link and Josephson Junction Devices-SQUIDS and Slugs- 37b1 SQUIDS- 37b2 Slugs- 4 Phonon Drag- 41 Introduction and General Relations- 42 Sg at High Temperatures- 43 Sg at Low Temperatures- 43a Low-Temperature Phonon Drag in the Alkali Metals- 43b Low-Temperature Phonon Drag in Other Metals- 44 Anisotropy of Relaxation Times and Phonon-Drag Thermopower- 45 Sg at Intermediate Temperatures- 46 Sg of Alloys- 47 Phonon Drag or Phony Phonon Drag?- 47a Pure Metals- 47b Dilute Alloys- 47c Evidence for "Phony Phonon Drag"- 47d Effects of Higher-Order Scattering Processes- 5 The Thermoelectric Power of Transition Metals- 51 Special Problems in Transition Metals- 51a s- and d-Conduction- 51b Electron-Electron Collisions- 51c Magnetic Effects: Collective Electrons and Isolated Spins- 51d Magnetic Effects: Magnons and Paramagnons- 51e Magnetic Effects: Spin Mixing- 51f Magnetic Effects: The Curie and Neel Temperatures- 52 The Diffusion Thermopower of Transition Metals- 52a Phonons and Impurities- 52b Electron-Electron Scattering- 52c Magnons and Paramagnons- 52d Two-Current Conduction and Spin Mixing- 52e Curie Point Anomalies- 53 The Phonon-Drag Thermopower of Transition Metals- 54 Magnon Drag- 55 Transition Elements: Summary of Experimental Results- 55a The Magnetic Elements: Cr, Mn, Fe, Co, and Ni- 55b The "Thermocouple" Elements: Fe, Pt, Re, and W- 56 Commercial Thermocouples- 56a Copper vs Constantan (Type T)- 56b Iron vs Constantan (Type J)- 56c Chromel vs Constantan (Type E)- 56d Chromel vs Alumel (Type K)- 56e Tungsten vs Tungsten-Rhenium (Types G* and C*)- 56f Platinum vs Platinum-Rhodium (Types R, S, and B)- 6 Dilute Magnetic Alloys- 61 Introduction- 62 The Virtual Bound State- 62a Electronic Properties for VBS Systems- 62b Survey of Experimental Results for VBS Systems- 63 Kondo Alloys- 63a Theory of the Kondo Effect- 63b Thermoelectric Power of Kondo Alloys- 64 Spin-Fluctuation Models- 65 Closing Comment- 7 Effects of Pressure and Magnetic Field on the Thermoelectric Power- 71 Pressure Dependence- 71a Introduction- 71b Practical Thermocouples- 71c Fundamental Studies- 71c1 Diffusion Thermopower- 71c2 Phonon-Drag Thermopower- 72 Magnetic Field Dependence- 72a Introduction- 72b Practical Thermocouples- 72c Fundamental Studies- 72d Landau Quantization Effects- References- Author Index
529 citations
TL;DR: In this article, an energy band model of amorphous GexSe1-x films has been proposed for consistent explanations of experimental data, and measurements of the photoconductivity and the absorption spectra have been made at room temperature.
Abstract: Measurements of electrical and optical properties have been made on GexSe1-x amorphous thin films of about 1 µm thickness. From the experiment of electrical conductivity at various temperatures, two processes of the d.c. conductivity in GexSe1-x films are observed in plots of ln σ against 1/T. The thermoelectric power exhibits a maximum value of p-type conduction at pure Se and a change of the sign from positive to negative at 0.4
165 citations
TL;DR: In this paper, the magnetic susceptibility, resistivity, specific heat, and thermoelectric power measurements on EuCu2Si2, YbCu2 Si2, EuSi2 and GdSi2 are presented, and the data are interpreted in terms of interconfiguration fluctuations (ICF).
Abstract: Magnetic susceptibility, resistivity, specific heat, and thermoelectric power measurements on EuCu2Si2, YbCu2Si2, CeCu2Si2, and GdCu2Si2 are presented. The first three compounds show a demagnetization of the 4f shell, while the fourth was studied to determine the “normal” magnetic and electronic properties for the RE-Cu2Si2 system. YbCu2Si2, CeCu2Si2, and EuCu2Si2 are found to exhibit similar lattice, electronic, and magnetic properties: an intermediate lattice constant; a magnetic susceptibility that is large and paramagnetic but neither shows order nor a Curie divergence; a large electronic specific heat coefficient; strong deviations from a simple T law in the high-temperature resistivity; and a large maximum in the thermoelectric power. The data are interpreted in terms of interconfiguration fluctuations (ICF), and a simple model is presented which can quantitatively explain the magnetic susceptibility and semiquantitatively predicts the specific heat. In addition, the model is in qualitative agreement with the resistivity and thermoelectric power data.
155 citations
TL;DR: In this paper, the anomalous behavior of the Seebeck coefficient below the Verwey temperature was interpreted with a model of mixed conduction, and the temperature range 80-300 K on five synthetic single crystals of magnetite, differing in oxygen stoichiometry.
Abstract: Thermolectric-power measurements were carried out in the temperature range 80-300 K on five synthetic single crystals of magnetite, ${\mathrm{Fe}}_{3}$${\mathrm{O}}_{4}$, differing in oxygen stoichiometry. The anomalous behavior of the Seebeck coefficient below the Verwey temperature was interpreted with a model of mixed conduction.
97 citations
65 citations
TL;DR: The thermal and electrical resistivity and Seebeck coefficient of heavily doped, pressure-sintered germanium-silicon alloy specimens have been measured in the temperature range 300-1200K.
Abstract: The thermal and electrical resistivity and Seebeck coefficient of heavily doped, pressure-sintered germanium-silicon alloy specimens have been measured in the temperature range 300-1200K. The thermal resistivity was considerably in excess of that for corresponding crystalline samples at temperatures below that of the thermal resistivity maximum; the temperature of this maximum was, however, about 75K below that found in crystalline samples. It proved possible to explain the data below the maximum by a Callaway-type thermal conductivity calculation including both free-carrier and boundary scattering of phonons. The boundary scattering mean free path was smaller than might have been expected from the grain size.
64 citations
TL;DR: The conductivity and thermoelectric power of single crystals of Fe 0.996 S have been recorded at temperatures between 80° and 530°K as discussed by the authors, and it appears to be a p-type semiconductor with band-gap 0.04 eV at low temperatures and a not-well-behaved metal above the phase transition at T α ≅420°K.
63 citations
61 citations
TL;DR: In this article, the electrical resistivity, temperature coefficient of resistance (TCR) and thermoelectric power were measured on systematically annealed copper films formed by the vacuum evaporation method.
Abstract: The electrical resistivity, temperature coefficient of resistance (TCR) and thermoelectric power are measured on systematically annealed copper films formed by the vacuum evaporation method. From the measured quantities the scattering coefficient and the bulk mean free path of the conduction electrons are calculated. The electron mean free path is found to be 410+or-100 AA. The energy dependence of mean free path U and the energy dependence of Fermi surface area V are calculated from the thermoelectric power measurements as a function of thickness. Both U and V are found to be negative and thickness-dependent.
52 citations
48 citations
TL;DR: In this article, the electrical conductivity and Seebeck coefficients have been measured from room temperature to 500°C for polycrystalline V 2O5 and V2O5 doped with lithium and sodium in the α-phase range.
Abstract: The electrical conductivity and Seebeck coefficients have been measured from room temperature to 500° C for polycrystalline V2O5 and V2O5 doped with lithium and sodium in the α-phase range. The conductivity increases with doping and the energy of activation decreases. The Seebeck coefficient indicates that electrons are the majority carriers. The results have been discussed in terms of the two-level hopping model.
TL;DR: In this article, conductivity, thermoelectric power and field effect measurements on amorphous Ge specimens prepared by the decomposition of germane gas in a rf glow discharge were investigated.
Abstract: The paper deals with conductivity, thermoelectric power and field effect measurements on amorphous Ge specimens prepared by the decomposition of germane gas in a rf glow discharge. Substrate temperatures T d of 300, 400 and 500 K were used during deposition. The sign of the thermoelectric power S is negative throughout the temperature range investigated (200–500 K). Above 300 K, the conductivity activation energy in specimens prepared at T d = 500 K lies between 0.40 and 0.43 eV; it is equal to the gradient of the S versus 1/ T curves, suggesting transport in the extended electron states. Below room temperature there is an increasing contribution in all specimens from electron hopping transport in localized states lying about 0.25 eV below ϵ C . Both conductivity and thermoelectric power results can be interpreted satisfactorily in terms of these two current paths. Hopping at the Fermi level has not been observed. The preliminary field effect measurements indicate that, as in amorphous Si, ϵ f lies near a density of state minimum. The density of states at ϵ f is appreciably higher than that in similarly prepared Si specimens.
TL;DR: In this article, the authors measured the thermoelectric power of the organic solid solutions (TTF1-xTSeFx)-TCNQ from 300 to 20 K.
TL;DR: In this article, low-temperature transport measurements were performed for pure bismuth and for a modified version with equal amounts of tin and tellurium, and it was shown that the compensated sample acts as a compensated semimetal with pronounced impurity scattering.
Abstract: Low-temperature transport measurements are reported for pure bismuth and for bismuth doped with equal amounts of tin and tellurium. Electrical resistivity and thermoelectric power data indicate that the compensated sample acts as a compensated semimetal with pronounced impurity scattering. If a rigid-band model and the validity of Matthiessen's rule are assumed, then it appears that the tin and tellurium act as a kind of neutral complex yielding a temperature independent scattering mechanism for electrons and holes.
TL;DR: In this article, the authors investigated the electrical and magnetic properties of EuB 6, La x Eu 1 − x B 6, YbB 6 and SmB 6 over the temperature range 4.2-800 K.
Abstract: The electrical and magnetic properties of EuB 6 , La x Eu 1 − x B 6 , YbB 6 and SmB 6 have been investigated over the temperature range 4.2–800 K. EuB 6 and YbB 6 , in which europium and ytterbium are in the +II oxidation state, are semiconductors. For the La x Eu 1 − x B 6 solid solutions, a sharp change from semiconducting to metallic behaviour is observed between x = 0 and x = 0.01. The relationships of x to conductivity, Seebeck coefficient, and magnetic properties are discussed in terms of a band model in which the conduction band is the 5 d − 6 s band of the rare-earth atom sublattice. The assumption is made that chemical inhomogeneities could produce a finite range of compositions over which the Seebeck coefficient changes from a metallic character towards a small-polaron character with decreasing x . The variation with x of the paramagnetic Curie temperature in the range 0–0.33 is attributed to an indirect exchange of the RKKY type via conduction electrons. The peculiar properties of SmB 6 are discussed using the same band model.
TL;DR: In this paper, a new technique is described for the continuous and rapid measurement of the thermo-electric power of substances as a function of either temperature or pressure, which involves the use of operational amplifiers.
Abstract: A new technique is described for the continuous and rapid measurement of the thermo-electric power of substances as a function of either temperature or pressure The circuitry involves the use of operational amplifiers-extremely efficient and versatile devices The overall accuracy of the instrument constructed out of this circuitry is within 1% The performance of the system is demonstrated by giving the experimental curve of thermopower against temperature in the case of ytterbium
TL;DR: In this paper, the temperature dependences of the mobility and thermoelectric power are calculated for pure mercury telluride, where the scattering of electrons by charged point centres and optical phonons is taken into account.
Abstract: The temperature dependences of the mobility and thermoelectric power are calculated for pure mercury telluride. The scattering of electrons by charged point centres and optical phonons is taken into account. The variational principle is used in the calculation because the relaxation time cannot be introduced for optical-phonon scattering. It is shown that the conduction-valence interband processes in optical-phonon scattering, possible in this zero-gap semiconductor, give an important contribution to the total scattering. It is demonstrated that the electron mobility in pure HgTe is determined by charged-point-centre and optical-phonon scattering and that the experimentally observed minimum of the conductivity between 30K and 50K can be explained by the interband resonant contribution to optical scattering.
TL;DR: In this paper, it was shown that the presence of small amounts of other oxidation states as an impurity in an otherwise pure sample can increase the electrical conductivity by 5 or 6 orders of magnitude.
Abstract: There is a large class of organic compounds which form stable radical ions at room temperature, that is they have a single electron in the highest occupied molecular orbital and carry a negative (e.g., tetracyanoquinodimethane) or a positive charge (e.g., tetracene tetrasulphide). They undergo simple one electron oxidation and reduction reactions and in the solid state these different oxidation states have high resistivities, generally > 1010 ohm cm. However, we have shown that the presence of small amounts (<1%) of other oxidation states as an impurity in an otherwise pure sample can increase the electrical conductivity by 5 or 6 orders of magnitude. The accompanying changes in the Seebeck Coefficient and activation energy for conduction arc of the order of 1 mv/°C and 0.5 ev respectively. These results are explained by assuming a hopping model of conduction and by postulating the existence of a redox equilibrium in the solid state.
TL;DR: In this paper, the authors measured resistivity, thermoelectric power and current noise on Li-doped MnO single crystals in the temperature range from 300 to 1000 K.
TL;DR: In this article, the electrical conductivity and thermoelectric power of concentrated lithium-methylamine solutions have been measured from - 73·5° to - 60°C.
Abstract: The electrical conductivity and thermoelectric power of concentrated lithium-methylamine solutions have been measured from - 73·5° to - 60°C. The solutions with XLi≳0·15 show metallic character. The results are discussed in terms of current models developed to explain metal-non-metal transitions and electronic transport properties in disordered materials
TL;DR: In this paper, the Hall coefficient RH, Seebeck coefficient, and electrical resistivity have been measured on hot-pressed SiGe alloys (80 at.% Si) from 4 to 300 K. In the analysis of the transport data the standard treatment of ionized impurity scattering was found to be inadequate.
Abstract: The Hall coefficient RH, Seebeck coefficient, and electrical resistivity have been measured on hot‐pressed SiGe alloys (80 at.% Si) from 4 to 300 K. The alloys were doped with As, P, or As+P from 5×1018 to 1.75×1020 cm−3. Only slight differences in transport properties with dopant type were observed. Studies of dopant solubilities were pursued, and the results suggest that the limiting electrical active As concentrations are below those of P. In the analysis of the transport data the standard treatment of ionized impurity scattering was found to be inadequate. The theory, when modified to include the energfy dependence of the screening factor, gives an adequate description of our data. Hall factors were determined from RH data and dopant concentrations obtained from chemical analysis. Hall factor were also determined from analysis of the transport data and were about 20% smaller than those based on dopant concentrations deduced from chemical analysis.
TL;DR: In this article, a two-temperature annealing technique was used to reduce defect concentrations as low as 5.5 × 1017 cm-3 and 5.0 x 1017cm-3 at 600°C.
Abstract: By using a two-temperature annealing technique to reduce native defect concentrations we have achieved carrier concentrations as low as 5. 6 x l015 cm-3 in bulk single crystals of PbS. Hall coef-ficient, electrical resistivity, thermoelectric power, infrared absorption coefficient, and CO2 laser transmission scan measure-ments were carried out for various samples in the carrier con-centration range from 5. 6 x l015 cm-3 to 4. 8 x 1018 cm-3. The low-temperature carrier concentration data were analyzed using a quantitative theory for the native defect concentrations as a function of the sulfur vapor pressure. Calculations based on this theory yield good agreement with experiment for intrinsic carrier concentration and defect equilibrium coefficient values of 5.5 x 1017 cm-3 and 5. 0 x 1017 cm-3, respectively, at 600°C.
TL;DR: In this article, the thermoelectric power of Ag4KI5 and Ag4RbI5 is measured between room temperature and few degrees below their melting points using silver electrodes.
Abstract: The thermoelectric power ( theta ) of Ag4KI5 and Ag4RbI5 is measured between room temperature and few degrees below their melting points using silver electrodes. The behaviour of theta with temperature can be expressed by the equations - theta =0.088(103/T)+0.310(mVK-1), (40-240 degrees C) and - theta =0.086(103/T)+0.338(mVK-1), (40-225 degrees C) respectively, for the two solids. A theoretical analysis of the data gives 0.088 and 0.086 eV for the heats of transport of Ag+ ions which are very close to the respective activation energies, in accordance with the prediction of the free-ion theory of Rice and Roth (1972) as well as that of the earlier theory on the heats of transport.
TL;DR: In this paper, the 4f→5d electronic phase transition in SmS has been studied using thermoelectric power as a probe and the variation of thermopower with pressure in Sm0.84Gd0.16S and in the high pressure phase of SmS is anomalous, characterized by a rather large pressure coefficient.
01 Jan 1976
TL;DR: In this article, the thermal conductivity, electrical resistivity, and absolute Seebeck coefficient of pure aluminum were determined from 80 to 400 K by measuring all three properties of samples with resistivity ratios of 11 × 103, 8.5 × 103 and 9.5× 102 using three different techniques.
Abstract: The thermal conductivity, electrical resistivity, and absolute Seebeck coefficient of pure aluminum were determined from 80 to 400 K by measuring all three properties of samples with resistivity ratios of 11 × 103, 8.5 × 103, and 9.5 × 102 using three different techniques. Measurements were made on the purest sample down to 20 K. The thermal conductivity has a broad plateau from 180 to 400 K and a possible minimum of 0.25% which is insignificant compared to the experimental errors. The same properties were measured on an aluminum alloy with a resistivity ratio of 17. Measured values of the thermal conductivity of this alloy agreed to within ±1% with calculated values using parameters obtained from the pure aluminum.
TL;DR: In this article, the authors evaluated the thermoelectric power of a semiconductor of the n -Germanium type under the conditions of elastic-acoustic phonon scattering and the high-temperature limit of the phonon distribution.
TL;DR: In this article, the effect of vacancies and dislocations on Hall coefficient and thermoelectric power of copper films has been deduced from annealing behaviour of various transport properties.
Journal Article•
01 Jan 1976-Science reports of the Research Institutes, Tohoku University. Ser. A, Physics, chemistry and metallurgy
TL;DR: In this article, the temperature dependence of electric conductivity and Hall effect in amorphous 60 percent Cu-40 percent Zr alloy was examined, and it was found that the temperature coefficient of the resistivity is negative at temperatures below the crystallization temperature of 7500K, and the signs of the Hall coefficient and thermoelectric power are positive.
Abstract: The temperature dependence of electric conductivity and Hall effect in amorphous 60 percent Cu--40 percent Zr alloy was examined. It was found that the temperature coefficient of the resistivity is negative at temperatures below the crystallization temperature of 7500K, and the signs of the Hall coefficient and thermoelectric power are positive.
TL;DR: In this article, the temperature dependence of electric conductivity and Hall effect in amorphous 60 percent Cu-40 percent Zr alloy was examined, and it was found that the temperature coefficient of the resistivity is negative at temperatures below the crystallization temperature of 7500K, and the signs of the Hall coefficient and thermoelectric power are positive.