Hall Coefficient Of Liquid Metals Research Articles

On the Hall coefficient of liquid metals

The theory of the Hall effect developed by Fukuyama, Ebisawa and Wada (1969) is reconsidered in the light of the mass renormalisation corrections found recently by Itoh and Watabe (1984). The result of Fukuyama et al, RH=(1/nec)g-2 where g is the Mott factor, requires correction; the basically free-electron result is obtained within self-consistent second-order perturbation theory (Edward's theory).

Spin-orbit coupling and the Hall coefficient of liquid metals

The effect of spin-orbit coupling on the Hall coefficient of simple liquid metals is discussed. Through use of the dynamic equations, an expression for the additional contribution due to spin-orbit coupling is obtained.

Nearly free electron theory of the Hall effect

A force-force correlation function formalism is used to obtain the memory function to lowest order in the scattering and first order in the magnetic field, and the resistivity tensor and Hall coefficient are thus obtained. At sufficiently high temperatures the independent particle expression for the Hall coefficient can be written in terms of the resistivity, density of states at the Fermi level and thermoelectric power. Comparison with experiment in this form indicates that the nearly free electron theory is inadequate to explain the closeness of the Hall coefficients of liquid metals to the free electron values.

A new mechanism for the anomalous hall coefficient with application to liquid metals

The effect of spin-orbit coupling of conduction electrons on the Hall coefficient of liquid metals is studied and a new mechanism for the anomalous Hall coefficient is suggested. S.O. coupling causes asymmetric scattering and a current, perpendicular to the magnetic field and to the electric field, is set up. This leads to an additional Hall coefficient\(\tilde R_{so} \), as was first calculated by Luttinger. But S.O. coupling also causes a dipole to appear near each ion, leading to an electrical polarization and an additional Hall coefficient,Rso.Rso is calculated for liquid normal metals and transition metals to first order in S.O. coupling. In normal metals,Rso and\(\tilde R_{so} \) are proportional to the Pauli susceptibility. Both are positive for electron-like charge carriers. S.O. coupling leads to a maximum deviation from nearly free electron value in the Hall coefficient of a heavy, four or five-valent liquid metal with short mean free path. In transition metals, different expressions are obtained forRso depending whether localized moments are present (magnetic model) or not (non-magnetic model). The sign ofRso is determined by the value of thed-phase shift alone.Rso is proportional to the susceptibility ofd-electrons and can be large, leading to a positive Hall coefficient in the liquid transition metal.

Hall Coefficients of Liquid Metals

A very accurate experimental technique is described for the measurement of the Hall coefficients of liquid metals. Measurements having an error factor of 4 less than that of previous work have been made on Hg, In, Tl, and Pb. For Hg and In, the measured Hall coefficient is equal to the free electron value, or the value obtained from an electron concentration equal to the atomic concentration times the valency, 2 for Hg and 3 for In. For Tl and Pb, the measured Hall coefficiert is about 18 and 32% smaller than the respective free electron values, corresponding to a valency of 3 for Tl and 4 for Pb. (H.D.R.)

Etching polished depressions in glass plates

It is pointed out that the hydrofluoric acid etching technique can be used to produce uniform polished depressions as much as 25μm deep in polished quartz, Pyrex and soda-glass plates. Such depressions can be used, amongst other things, in the construction of cells for the determination of the Hall coefficients of liquid metals.

The Hall Effect in Liquid Metals

A direct current method suitable for the measurement of the Hall coefficient of liquid metals (RL) up to temperatures of about 760 °c is described. It has been applied to cadmium, indium, lead, mercury and zinc and the values of RL so obtained, accurate to about ±6%, are close to those predicted by the free electron theory. Although general agreement is obtained with determinations made by alternating current methods by Busch and Tieche in 1962 and Wilson in 1962 some important differences emerge. The significant departure of RL from the free electron value reported by Busch and Tieche for lead and by Wilson for indium has not been confirmed. For the liquid divalent metals, where the temperature coefficient of resistivity is anomalous, care was taken to establish any temperature dependence of RL. No such dependence would be detected over a temperature range greater than that in other investigations. Some theoretical implications of this work are discussed.

Hall coefficients of liquid metals

A very accurate experimental technique is described for the measurement of the Hall coefficients of liquid metals. Measurements having an error factor of 4 less than that of previous work have been made on Hg, In, Tl, and Pb. For Hg and In, the measured Hall coefficient is equal to the free electron value, or the value obtained from an electron concentration equal to the atomic concentration times the valency, 2 for Hg and 3 for In. For Tl and Pb, the measured Hall coefficiert is about 18 and 32% smaller than the respective free electron values, corresponding to a valency of 3 for Tl and 4 for Pb. (H.D.R.)

The hall coefficient of liquid mercury

Abstract A technique for measuring the Hall coefficient of liquid metals is described. Results for solid and liquid mercury are presented and discussed. The Hall coefficient for liquid mercury is found to be -75 × 10−5 e.m.u. over the temperature range -38.9°c to + 100°c.

Halls effect in liquid and solid mercury

Abstract UNTIL about 1930 there was some doubt as to whether liquid metals showed Hall effects. In 1914, Fenninger failed to find Hall voltages in liquid Hg, but he also found a zero effect in solid Hg and the latter result has been contradicted in at least two subsequent experiments. In 1931, Kikoin and Fakidow showed that a liquid Na-K alloy possessed a Hall coefficient approximately equal to the free electron value of—1/nec, where n is the number of conduction electrons per unit volume. Nevertheless they too concluded that liquid Hg has zero Hall effect. Taken in conjunction with later results for solid Hg (e.g. those of Serduke and Fisher 1932), this would mean that the Hall coefficient, R, changes considerably on melting. It seemed desirable to check this result in the course of developing apparatus for investigating the Hall coefficient of liquid metals generally.