Electronic structure of cobalt disilicide

The electronic structure of ${\mathrm{CoSi}}_2$ at the Fermi level has been investigated by means of the de Haas–van Alphen effect in pure crystals. The measured Fermi-surface areas may be understood in terms of three bands crossing the Fermi level as predicted in a recent energy band calculation of Mattheiss and Hamann (following paper). The experimental and the predicted areas associated with all three bands are found to agree to a remarkable accuracy of better than 6%, while the measured cyclotron masses exceed the calculated masses by 40% to 100% for the smallest and the largest Fermi-surface sheets, respectively. The latter result points to a substantial and anisotropic suppression of the slopes of the quasiparticle bands at the Fermi level due to the electron-electron and electron-phonon interactions.