Helicon Waves, Surface-Mode Loss, and the Accurate Determination of the Hall Coefficients of Aluminum, Indium, Sodium, and Potassium

Abstract

Observations of helicon wave resonances in some metals have been interpreted by various investigators as implying values for the Hall coefficients of these metals which are significantly higher than the theoretical values. This interpretation resulted from using an approximate solution to the relevant boundary-value problem, without a full appreciation of the extent of the errors which were thereby incurred. In 1964, Legéndy critically discussed the boundary conditions and gave several solutions. His solution for an infinite cylinder parallel to the static magnetic field is particularly interesting in that it predicts the existence of a surface mode whose total power dissipation is virtually independent of the resistivity of the material. This paper presents a detailed quantitative experimental confirmation of the accuracy of this solution, thus validating the boundary condition used. The observations also yield values for the Hall coefficients of aluminum, indium, sodium, and potassium which are equal to the theoretical values to within the experimental accuracy of about ½%.