We present results of linear muffin-tin-orbital band-structure calculations of ErAs in the local-spin-density approximation. While the exchange splitting and cyclotron masses are in good agreement with experimental data, we find the Fermi surface dimensions of this semimetal to be significantly overestimated. A good fit to recently measured Shubnikov-de Haas oscillations in ${\mathrm{Er}}_{\mathrm{x}}$${\mathrm{Sc}}_{1\mathrm{-}\mathrm{x}}$As is obtained when the ${\mathrm{\Delta }}_2^{\prime }$ band is shifted upward by a quasiparticle self-energy correction. The effects due to alloying with Sc are taken into account in a virtual-crystal approximation.

• Received 23 May 1994

DOI:https://doi.org/10.1103/PhysRevB.50.7800