Showing papers on "Seebeck coefficient published in 1969"
TL;DR: A survey of the experimental data for the thermoelectric power of transition metals can be found in this paper, where the authors present a critical review of the main data, which are given in the literature and proved to be rather incomplete.
Abstract: This paper is concerned with a survey of the experimental data for the thermoelectric power† The thermoelectric power is hereinafter referred to as TEP of transition metals and with their discussion. For the first time a critical review of the main data, which are given in the literature and proved to be rather incomplete, is presented. When necessary, the author has conducted the TEP measurements within the temperature range of 80° to 1800°k, wherever it was possible. For the first time TEP data have been obtained for scandium, osmium and, effectively, for hafnium; erroneous data for thorium and ruthenium have been corrected; the temperature measuring range for many other metals has been substantially extended. Finally, from the data found in the literature and the new results, a fairly complete notion has been formed of the high-temperature behaviour of TEP for all transition metals (except technetium) in the 3d, 4d, and 5d series of the periodic system, as well as for uranium and thorium. Some...
71 citations
TL;DR: In this article, the electrical conductivity and thermoelectric power of the liquid T1 + Se and T 1 + Te systems have been measured as a function of concentration and temperature.
Abstract: The electrical conductivity and thermoelectric power of the liquid T1 + Se and T1 + Te systems have been measured as a function of concentration and temperature. Both of the systems show a deep minimum in the electrical conductivity at the composition corresponding to T12Se and T12Te. The absolute thermoelectric power changes its sign around this composition, being negative for the T1-rich solutions and positive for the Se- and Te-rich solutions. The impurity effect was examined in the T12Se melt. The electrical conductivity of the saturation range, where the carrier density can be considered to be constant, is discussed in the light of the scattering model.
69 citations
TL;DR: In this article, electrical resistivity, thermoelectric power, and magnetic susceptibility or magnetization have been measured at room temperature and below on compositions surrounding NiAl (49-51 at. % Al) and CoAl (42-54% Al).
59 citations
TL;DR: In this paper, the phase relation and electric and magnetic properties of Li x V 2−x O 2 were studied in the temperature range from liquid helium to 400°C, and the one phase region was determined to be in the range of 0.8≤x≤1.2 in Li xV 2−X O 2.
58 citations
TL;DR: In this article, the thermoelectric power and electrical conductivity of NbO were measured as functions of temperature at the limiting oxygen activities for the thermodynamic stability of each of the compounds.
50 citations
TL;DR: In this article, the shape of the Fermi surface relative to the Brillouin zone is analyzed and the Hall coefficient shows proportionality to the electrical conductivity and changes the sign twice within the homogeneity range.
49 citations
TL;DR: In this article, the Hall coefficient and the conductivity have been measured as a function of temperature for liquid Au2Te, CuTe, AgTe and Tl-Te and the results show that both p and n-type conduction occurs in these materials, depending on the composition.
Abstract: The Hall coefficient and the conductivity have been measured as a function of temperature for liquid Au2Te, CuTe and AgTe and as a function of temperature and composition for the liquid alloy systems Bi-Te and Tl-Te. The electrical properties of liquid Cu-Te, Ag-Te and Tl-Te seem to resemble those of a heavily doped semiconductor. The thermoelectric power data of Cutler and Mallon and of Dancy suggest that both p and n-type conduction occurs in these materials, depending on the composition. By contrast the Hall coefficient appears to be consistently negative and several explanations of this discrepancy are discussed.
49 citations
TL;DR: The electrical conductivity and Seebeck coefficient of single crystal calcium titanate were measured as a function of temperature and P H 2 O ⧸ p H 2, and the results may be described by a majority defect model consisting of doubly ionized oxygen vacancies and electrons as mentioned in this paper.
47 citations
39 citations
TL;DR: The thermoelectric power along the basal plane of a synthetic single-crystal graphite has been measured in the temperature range from 300°K down to 7°K as discussed by the authors.
Abstract: The thermoelectric power (TEP) along the basal plane of a synthetic single-crystal graphite has been measured in the temperature range from 300°K down to 7°K. The TEP versus temperature diagram exh...
37 citations
TL;DR: In this article, the binary alloy systems In-Sb, Bi-Te, Sb-Te and In-Te have been investigated in respect of their electrical conduction propertics in the liquid state.
Abstract: The binary alloy systems In-Sb, Bi-Te, Sb-Te and In-Te have been investigated in respect of their electrical conduction propertics in the liquid state. Measurements of resistivity, thermoelectric power and Hall coefficient have been made and indicate the existence of strong positional correlation of ions in the liquid state. This occurs for a range of alloy compositions, not only in the stoichionietric phases.
TL;DR: In this article, the preparation of amorphous alloys of Mg-Bi by vapour quenching of the constituent elements is described, and the electrical conductivity and thermoelectric power of the alloys as a function of temperature and composition are discussed.
Abstract: The preparation of amorphous alloys of Mg-Bi by vapour quenching of the constituent elements is described. The electrical conductivity and thermoelectric power of the alloys as a function of temperature and composition are discussed, particular attention being given to the behaviour near the intermetallic compound (Mg3Bi2) composition. Here the properties are found to be in agreement with a model of localized electron states, with the electrons moving by thermally activated hopping.
TL;DR: In this paper, a series of samples of the semiconducting ferromagnetic compound CdCr2Se4, doped with varying amounts of indium, was used to investigate the behavior of resistivities ρ, normal Hall coefficients R0, and Seebeck coefficients Q, and showed that from room temperature down to 150°K the electrons deionize onto the donor centers.
Abstract: Electrical resistivities ρ, normal Hall coefficients R0, and Seebeck coefficients Q, are reported for a series of samples of the semiconducting ferromagnetic compound CdCr2Se4, doped with varying amounts of indium. The behavior of ρ and of R0 indicates that from room temperature down to 150°K the electrons deionize onto the donor centers. From 150°K down to about 55°K, the carrier concentration increases by approximately four orders of magnitude, accompanied by a proportional drop in ρ; this can be attributed to the known decrease in bandgap with lowering of T, if the donor level is assumed to remain constant with reference to the valence‐band edge. The rise of ρ below 55°K is ascribed to impurity conduction. The mobilities reach a maximum near Tc, and fall off on both sides. Strong dependence of R0 on the magnetic field H is found above 110°K. The magnetoresistance is negative, and peaks sharply at 130°K; it obeys different power laws on the two sides of its peak. The Seebeck coefficient Q shows unique d...
TL;DR: In this paper, the temperature dependence of electrical resistivity, Seebeck coefficient, and the saturation magnetization were performed on polycrystals Cu 0.5 Fe 2.5 O 4+γ.
Abstract: The measurements of the temperature dependence of electrical resistivity, Seebeck coefficient, and the saturation magnetization were performed on polycrystals Cu 0.5 Fe 2.5 O 4+γ With all samples the anomalous behavior above 400°C was observed which manifested itself by a sudden increase of electrical resistivity, by the change from n- to p- type of electrical conductivity, and by the irreversible course of the magnetization. Contrary to physical properties, the chemical analysis revealed no significant changes in the composition of ferrites during the transformation. Taking into account the electrical, magnetic, and X-ray investigation it was concluded that in quenched samples (Cu1++ Fe3+) and Cu2++ Fe2+) pairs are more stable in the tetrahedral and the octahedral sites of the spinel lattice, respectively. After the transformation only Cu1+and Fe3+are present in the ferrites which initiates their decomposition into haematite and delafossite.
TL;DR: In this article, the authors measured the Hall, Seebeck and transverse Nernst-Ettings-hansen effects over the temperature range from 100°K to 500°K on Cu3SbSe4.
Abstract: Electrical and thermal conductivity and Hall, Seebeck and transverse Nernst-Ettings-hansen effects have been measured over the temperature range from 100°K to 500°K on Cu3SbSe4. From the temperature dependence of the Hall coefficient, the electron to hole mobility ratio is estimated to be about three. Temperature dependences of the resistivity and the Hall coefficient give an estimate of 0.13 eV for the energy gap at 0°K. The infrared transmission spectra at room temperature also showed a threshold of absorption at about 0.11 eV of photon energy. From the Seebeck coefficient data, the effective mass of holes is calculated to be 0.73 m0. The scattering parameter is determined to be zero over the temperature range studied which is the value expected for acoustic mode lattice scattering. The lattice thermal conductivity varies with temperature as T-1. The dimensionless thermoelectric figure of merit, ZT, is evaluated as a function of temperature and the reduced Fermi level.
TL;DR: In this paper, the Hall constant and thermopower have been measured in single-crystal V2O3 at temperatures up to 800°K R in the metallic phase is n-type, independent of temperature and corresponds to 0·6 carriers per vanadium atom.
Abstract: The Hall constant (R) and thermopower have been measured in single-crystal V2O3 at temperatures up to 800°K R in the ‘metallic’ phase is n-type, independent of temperature and corresponds to 0·6 carriers per vanadium atom The conductivity of V2O3 and VO2 crystals has been measured down to 7°K Below ∼40°K there is evidence of impurity conduction with activation energies of order 0·001 ev We infer that the ‘metallic’ state is not due to a high density Fermi gas moving in a narrow band Recent models are examined, which propose mixed conduction with or without polaron formation, and a comparison is made with VO2 and Fe3O4
TL;DR: In this article, the electrical resistivity and Seebeck coefficient have been measured on a series of hot-pressed Ge-Si alloys over the temperature range 300-1200 °K and Hall mobility in the range 300 -1000 °K.
Abstract: The electrical resistivity and Seebeck coefficient have been measured on a series of hot-pressed Ge-Si alloys over the temperature range 300-1200 °K and Hall mobility in the range 300-1000 °K. The results indicate that some specimens possess mobilities and Seebeck coefficients close to single-crystal values. Making use of available thermal resistivity data the maximum efficiency of a single couple generating device constructed from the best p-type and n-type alloys was computed to be 8% when operating between 300-1000 °K.
TL;DR: In this paper, the thickness dependence of the Seebeck coefficient for Ni films of variable thickness on bulk Au was determined and found to be sensitive to the thermal history of the thin film thermocouples.
Abstract: Continued investigations of the thermoelectric properties of Au–Ni thin‐film thermocouples have been made. The thickness dependence of the Seebeck coefficient for Ni films of variable thickness on bulk Au was determined and found to be sensitive to the thermal history of the thin film thermocouples. By developing suitable preparation techniques for these thermocouples, involving several periods of annealing, time‐invariant calibration curves were obtained. The thickness dependence of the Seebeck coefficient was found to follow closely the predictions of the size‐effect theory of Mayer.
TL;DR: The thermoelectric power of europium has been determined between 10 and 300°K using samples in the well-annealed, as-received and highly strained conditions as discussed by the authors.
Abstract: The thermoelectric power of europium has been determined between 10 and 300°K using samples in the well-annealed, as-received and highly strained conditions. The effect on the thermoelectric power of the transition to antiferromagnetism below 88.8±0.1°K and of magnon drag at lower temperatures is discussed and compared with deductions made from accompanying resistivity data. The temperature at which a small anomaly, caused by an impurity, occurs in the most strained sample (25°K) is lowered to 18°K as the sample strain and probably also hydrogen contamination decreases. The nature of this behavior is discussed.
TL;DR: In this paper, a theoretical explanation of the anomalous feature of the Nernst-Etting-shausen coefficient A N E in bismuth is presented.
Abstract: Theoretical explanation of the anomalous feature of the Nernst-Etting-shausen coefficient A N E in bismuth is presented. Temperature dependence of A N E is entirely different from the one predicted by a theory ignoring the deviation of the phonon distribution. Coupled Boltzmann equations for carriers and phonons are solved on the weak field approximation. These solutions reveal to us that the phonon drag effect and the indirect interactions of electrons and holes through the phonon drag effect, are responsible for the appearance of the anomalous effect. In strong magnetic field A N E is related to the phonon drag thermoelectric power derived in the preceding paper. This relation explains the qualitative feature of A N E at low temperatures.
TL;DR: In this article, the superconducting galvanometer of Clarke has been applied to measurements of thermopower in metals and experimental results show that the sensitivity is at least 100 times greater than has been previously achieved in such measurements.
Abstract: The superconducting galvanometer of Clarke has been applied to measurements of thermopower in metals. Experimental results are presented to show that the sensitivity is at least 100 times greater than has been previously achieved in such measurements.
TL;DR: In this paper, anomalous behavior of the thermoelectric power of thin Bi films has been observed and the results are consistent with those anticipated, based on both quantum and classical size effects in scattering.
Abstract: Anomalous behaviour of the thermoelectric power of thin Bi films has been observed and the results are consistent with those anticipated, based on both quantum and classical size effects in scattering. Mayer's theory relating thermoelectric power to film thickness can be applied to the present results provided that the bulk conduction electron mean free path is used for calculations of the thermoelectric power of thick specimens and that the conduction electron de Broglie wavelength is used for thin specimens.
TL;DR: The Seebeck and Nernst coefficients of several samples of Cd3As2 have been measured, in transverse magnetic fields of up to 2 tesla, between liquid nitrogen and room temperature.
Abstract: The Seebeck and Nernst coefficients of several samples of Cd3As2 have been measured, in transverse magnetic fields of up to 2 tesla, between liquid nitrogen and room temperature. The saturation high-field Seebeck coefficient has been determined by extrapolation of the results of these measurements, taking into account inelastic scattering of the electrons. From the interdependence of the high-field Seebeck and Hall coefficients, it appears that the conduction band is linear, i.e. E is proportional to k. Thence, from the difference between the high- and low-field Seebeck coefficients, the scattering law has been determined. If the relaxation time τ is supposed to be proportional to k2λ-1dE/dk a value of λ equal to 07 is indicated.
01 Jul 1969
TL;DR: In this article, an experimental method is derived, which distinguishes and measures the effect of various factors on a given type of thermocouple, and which enables the results to be used to calculate the performance of the thermometer under given conditions, such as as-received inhomogeneity, plastic strain and heating up to 650°C.
Abstract: Hitherto, no quantitative relationship between errors in thermoelectric thermometers and their causes (i.e. changes in Seebeck coefficient and temperature distribution) has been demonstrated. A theory of the operation of thermocouples has therefore been developed. From this, an experimental method is derived, which distinguishes and measures the effect of various factors on a given type of thermocouple, and which enables the results to be used to calculate the performance of the thermocouple under given conditions. The effects of as-received inhomogeneity, plastic strain and heating up to 650°C are given for chromel-alumel, and in less detail for other common materials. It is shown that it is possible to predict drift and other instabilities in chromel-alumel under defined conditions, and reduce the uncertainty of measurements by an order of magnitude in favourable cases. It is also shown that the conventional concepts of calibration which are widely used in the application and investigation of the performance of thermocouples, are generally fallacious.
TL;DR: Theoretical interpretation of an anomalous behavior of the thermoelectric effect in bismuth is presented by Farag and Tanuma as discussed by the authors, who show that the power has sharp minimum at low temperatur...
Abstract: Theoretical interpretation of an anomalous behavior of the thermoelectric effect in bismuth is presented. According to Farag and Tanuma, the thermoelectric power has sharp minimum at low temperatur...
TL;DR: In this paper, the electrical resistivity ϱ and the Seebeck coefficient Θ were measured in the temperature range 80-800 °K on single crystals and polycrystals from the system of manganese-copper ferrites Cu0.5MnzFe2.
Abstract: The electrical resistivity ϱ and the Seebeck coefficient Θ were measured in the temperature range 80–800 °K on single crystals and polycrystals from the system of manganese-copper ferrites Cu0.5MnzFe2.5−zO4(0 ≦z 0.7) a new conduction mechanism plays a significant role which is probably due to the presence of the copper ions in those ferrites.
TL;DR: In this paper, a simple model with Kondo's theory accounts qualitatively for the observations of increased thermoelectric power with applied magnetic field, and it is shown that Fe-Fe interactions are responsible for an increase in thermoelection power.
Abstract: Fe–Fe interactions are shown to be responsible for an increase in thermoelectric power with applied magnetic field. A simple model, with Kondo's theory, accounts qualitatively for the observations....
TL;DR: In this article, TSC data yields an activation energy of 1.10 eV for the V, decay while the TEP results demonstrate that holes are the mobile charge carriers.