Thermoelectromotive Force Research Articles

白金，モリブデン合金の研究

Pt-Mo alloys were arc-melted in argon atmosphere. Their melting temperatures were measured, X-ray analyses and microscopical study were carried out. From these results the equilibrium diagram was constructed. This alloy system consists of three kinds of solid phases, i. e. the Pt-rich solid solution α an intermediate phase β corresponding to Pt-Mo compound and the Mo-rich solid solution γ. The liquidus of β phase shows a maximum and on the Pt-side a peritectic reaction Liquid+β\ ightleftharpoonsαoccurs and on the Mo-side there exists an eutectic reaction Liquid \ ightleftharpoonsβ+γThe electric resistance of Pt-rich alloys and the thermo-electromotive forces of Pt-(Pt-Mo) alloys were measured. The thermo-electromotive force shows a maximum value at about 3.5%Mo.

規則格子FeCo生成に関する実験的研究（その4）熱起電力，熱膨脹並びにX線による研究(1)

規則格子FeCo生成に関する実験的研究（その4）熱起電力，熱膨脹並びにX線による研究(1)

Some Experimental Studies of the Conductivity and Thermo-electromotive Force of Cs3Sb Photo-Cathodes II

Some Experimental Studies of the Conductivity and Thermo-electromotive Force of Cs₃Sb Photo-Cathodes II

Some Experimental Studies of the Conductivity and Thermo-electromotive Force of Cs3Sb Photo-Cathodes

Some Experimental Studies of the Conductivity and Thermo-electromotive Force of Cs₃Sb Photo-Cathodes

Thermoelectromotive Force of a Superconductor Versus the Same Metal in the non-Superconducting State

Thermoelectromotive Force of a Superconductor Versus the Same Metal in the non-Superconducting State

The Physical Properties of Cuprous Sulfides-Semiconductors

Cuprous sulfide has been observed to have two transition points at about 110°C and 470°C respectively, of which the latter one has been found out experimentally by the writer. The exsistence of the phase transition at 470°C has been confirmed experimentally by the measurements of electronic and ionic conductivity, thermal linear expansion, heat capacity, specific heat and thermo-electromotive force. We, therefore, propose that cuprous sulfide has three polymorphic phases, namely α-phase (above 470°C), β-phase (470°C∼110°C) and γ-phase (below 110°C). In the γ-phase it behaves as a P-type semiconductor (sulphur excess), and its electrical conductivity increases exponentially with temperature. In the β-phase, we have observed the rather remarkable ionic currents together with the sharp decrease of electronic currents. On proceeding to the α-phase, the ionic currents abruptly disappear and electronic currents increase to the larger amount than that in the γ-phase. The transition enery at 110°C has been observ...

Thermo-electromotive Force of BaO and (Ba-Sr)O

Thermo-electromotive Force of BaO and (Ba-Sr)O

Thermoelectromotive Force of a SuperconductorVersusthe Same Metal in the Non-Superconductive State

Thermoelectromotive Force of a Superconductor<i>Versus</i>the Same Metal in the Non-Superconductive State

半導体の研究（第3報）亜酸化銅の半導性に関する二，三の実験的考察

Cuprous oxide is one of the most important materials of semiconductor and a large number of studies about it has been carried out since the beginning of this century, but there are some discrepancies between the results of the measurements so far published, owing to the difficulties of these experiments. To make this problem clear and to furnish the fundamental data for the improvement of cuprous oxide rectlfier, the present authors have investigated the galvano-magnetic properties of cuprous oxide. We have measured the electrical conductivity, the thermo-electromotive force, the Hall effect, the magnetoresistance and the Nernst coefficients with respect to the cuprous oxide crystals made under various oxygen pressures over the temperatures ranging from 15° to 450° . From these measurements the concentrations, the mobilities, the effective masses and the mean free paths of positive holes and electrons were calculated as the functions of temperature. Summarizing these results, it may be considered that each crystal mentioned above is a P-type extrinsic semiconductor at low temperatures, while it is an intrinsic above 380°.

The Thermoelectromotive Force of Tin at the Superconducting-Normal Junction

The Thermoelectromotive Force of Tin at the Superconducting-Normal Junction

Thermoelectromotive Force of SuperconductingversusNormal Junctions of the Same Metal

Thermoelectromotive Force of Superconducting<i>versus</i>Normal Junctions of the Same Metal

The Theory of Thermoelectromotive Force in Semiconductors

The Theory of Thermoelectromotive Force in Semiconductors

A Note on the Thermoelectromotive Force

A Note on the Thermoelectromotive Force

On the Thermo-electromotive Force of Bismuth Thin Films

On the Thermo-electromotive Force of Bismuth Thin Films

Thermo-electromotive forces of a superconductor against the same metal in the non-superconductive state

Summary In connection with the fact that the thermo-eleotromotive forces in a thermocouple consisting of a superconductor A and another metal B, are affected by a magnetic field (cf. Commun. No. 250d), we have examined whether there is a thermo-electromotive force in a thermocouple in which the metal B has been replaced by the same metal A but with superconductivity disturbed by a magnetic field. Experiments were made on tin and on indium. For both metals a thermo-electromotive force as mentioned was found. For indium the agreement with the results of Commun. No. 250d is good. For tin such a comparison could not be made for want of experimental data. The results of the present experiments were further compared with the formula for the thermo-electromotive force for this case given by K o k in Commun. Suppl. No. 84a, and on broad lines agreement was found.

Thermo-electromotive forces of some superconductors in the neighbourhood of their transition points; the influence of a magnetic field

Thermo-electromotive forces of lead against a silveralloy-normal and against tin, and of indium against lead were measured at temperatures obtainable with liquid helium and with liquid hydrogen. The influence of a magnetic field was examined. The thermo-electromotive force between two superconductors is zero, also when a magnetic field, smaller than the threshold values for the two metals, is applied. The curve E (thermo-electromotive force) versus T for temperatures above the transition point of one of the two metals is shifted by the application of a magnetic field, in connection with the shifting the transition point undergoes. The curve e (thermoelectric power) versus T is continuous at the transition point as well in a magnetic field as when no magnetic field is applied; de/dT, however, is discontinuous in both cases. In a region of about one to two degrees above the transition point, either-in a magnetic field or not, e varies with the (longitudinal) magnetic field.

A duplex commutator and key of small thermoelectromotive force

A duplex commutator and key of small thermoelectromotive force

On the Thermo-Electromotive Force of the Brushcs for Electric Machines

On the Thermo-Electromotive Force of the Brushcs for Electric Machines

The Effect of Tension and a Longitudinal Magnetic Field on the Thermoelectro-Motive Forces in Permalloy

Measurements have been made on the combined effect of tension and a longitudinal magnetic field on the thermoelectromotive force in three specimens of permalloy. The specimens were in the form of wires, the composition being 78, 81 and 84 percent nickel with the remaining part iron. In all cases the magnetic field produces a decrease in the thermoelectromotive force. Annealing at 1000\ifmmode^\circ\else\textdegree\fi{}C increases the change of thermoelectromotive force produced by a longitudinal magnetic field. In an alloy containing 78 percent nickel tension decreases the maximal value of the change of thermoelectromotive force. In an alloy containing 81 percent nickel the maximal value of $\frac{\ensuremath{\Delta}E}{E}$ is relatively insentitive to tension. In an alloy containing 84 percent nickel tension decreases the change of thermoelectromotive force at low magnetic fields but increases it for magnetic fields greater than about 10 gauss. In all three cases the maximal value of $\frac{\ensuremath{\Delta}E}{E}$ is relatively insenitive to changes in tension beyond about 10 kg/${\mathrm{mm}}^{2}$. There is a parallelism between the change of length and change of thermo-electromotive force under the combined action of tension and a longitudinal magnetic field. In high-nickel permalloys tension decreases the intensity of magnetization for low magnetic fields but increases the magnetostrictive contraction and the change of thermoelectromotive force. In low-nickel permalloys tension increases the intensity of magnetization for low magnetic fields but decreases the magnetostrictive expansion and the change of thermoelectromotive force.

The Longitudinal Thermomagnetic Potential Difference in a Bismuth Crystal

The longitudinal thermomagnetic potential difference in a bismuth crystal has been measured at room temperature for various orientations of heat current, magnetic field, and crystal axis. The results are plotted to show the change of thermoelectromotive force as a function of magnetic field strength. When the heat current is parallel to the crystal axis the field produces an apparent increase of thermoelectromotive force, the maximum being about 7 percent in a field of 7000 gauss. When the heat current is perpendicular to the crystal axis the field produces a decrease of thermoelectromotive force, the maximum being 23 percent in a field of 7000. Some of the data are in poor agreement with previous work by Lownds and Defregger. The results may be explained qualitatively by assuming that a magnetic field produces a structural change of some sort in the atomic system of bismuth. This change, in the direction normal to the field, is essentially different from the change parallel to the field.