Fermi Surface of Magnesium. I. Magnetoacoustic Attenuation

Abstract

Geometric resonances in the ultrasonic attenuation have been studied in magnesium for sound propagated in the three principle crystallographic directions. A total of twenty different geometric resonance branches have been obtained. The assignment of these branches to Fermi-surface calipers shows that the magnesium Fermi surface is much more free-electron-like than currently thought. Three of the first four local pseudopotential Fourier expansion coefficients are estimated from data to be 5 × ${10}^{-4\mathrm{}}$ 1.0 × ${10}^{-2\mathrm{}}$, and 1.7 × ${10}^{-2\mathrm{}}$ Ry for the absolute value of the [$10\overline{1}0$], [0002], and [$10\overline{1}1$] coefficients, respectively. A two orthogonalized-plane-wave model is given for the lens-shaped piece of the Fermi surface in the third Brillouin zone, and various physical properties of this model are calculated and compared with experimental data.