De Haas-van Alphen measurement of the spin susceptibility andg-factor of the conduction electrons in the alkali metals

Abstract

Absolute amplitude measurements of the de Haas-van Alphen effect by a simple new technique, as well as harmonic content measurements, have been used to obtain three independent determinations of the gitg-factor and of the spin susceptibility χ of the conduction electrons in K and Rb. These three determinations are in fairly good agreement with each other, thus confirming the reliability of the theory on which they are based. The mean values ofg are 2.800±0.011 for K and 2.83±0.05 for Rb. Only one of the three techniques could be used for Cs, giving a provisional estimate ofg=2.44±0.11, although a value ofg=3.11±0.12 is also compatible with the results and cannot be ruled out. These results correspond to values of χ/χ0 (where χ0 is the free-electron spin susceptibility) of 1.700±0.006 for K, 1.724±0.010 for Rb, and 1.76±0.06 (or 2.24±0.06) for Cs, which are in fair agreement with determinations by other methods, though the present values for K and Rb are appreciably more accurate. The results are discussed within the framework of the Landau theory of Fermi liquids and values of the many-body parameterB 0 are deduced which are reasonably consistent with theory. By using the known cyclotron masses and also the results of far-infrared cyclotron resonance experiments for K, it proves possible to estimate the separate contributions to the many-body effects arising from electron-phonon and electron-electron interactions.