De Haas-Van Alphen Effect


de Haas-van Alphen effect

[də¦häs ‚van′äl·fən i‚fekt] (solid-state physics) An effect occurring in many complex metals at low temperatures, consisting of a periodic variation in the diamagnetic susceptibility of conduction electrons with changes in the component of the applied magnetic field at right angles to the principal axis of the crystal.

De Haas-Van Alphen Effect

 

an oscillating dependence of the magnetic susceptibility x of metals on the strength of the magnetic field H observed at temperatures near absolute zero. It was discovered by W. J. de Haas and P. M. van Alphen in 1930. In describing the de Haas-van Alphen effect, just as for the Shubnikov-de Haas effect, it is convenient to regard the dependence on 1/H rather than on H (Figure 1). The amplitude of the oscillations decreases with an increase in temperature. The oscillation period is related to the area of the extreme sections of the Fermi surface; consequently, the study of the de Haas-van Alphen effect makes it possible to obtain information about the shape of the surface.

Figure 1. Magnetic permeability of zinc as a function of 1/H at 4.2°K