Fermi surface of magnesium. I. Magnetoacoustic attenuation

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 1.0 × 10-2, and 1.7 × 10-2 Ry for the absolute value of the [101̄0], [0002], and [101̄1] 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.