Cyclotron Resonance and the Cohen Nonellipsoidal Nonparabolic Model for Bismuth

An equation for the cyclotron effective mass in the Cohen nonellipsoidal nonparabolic (NENP) model for Bi is derived for an arbitrary direction of the magnetic field. This equation is compared with the previously published cyclotron-resonance data of Kao and of Edel'man and Khaikin (EK). In both cases very good agreement between experiment and the NENP model is found for the binary-plane data, and the fit is clearly superior to that of the ellipsoidal nonparabolic (ENP) model; in the remaining orientations the experimental points suffer more scatter, but seem to fit the NENP model better than the ENP model. The quantity $\eta$, as defined by Bhargava, is recalculated using the $m^{*}$ values of EK rather than those of Kao. The value $\eta =1.13\mathrm{}\pm 0.05$ is found, confirming the NENP model.