Narrow-gap semiconducting silicides: the band structure

Electronic property simulation of the narrow-gap semiconducting rhenium and ruthenium silicides has been performed by the linear muffin-tin orbital me thod (LMTO) within the local density approximation. ReSi1.75 was found to h ave an indirect gap value of 0.16 eV. The first direct transition with appr eciable oscillator strength at 0.30 eV is predicted. Ru2Si3 is revealed to be a direct gap semiconductor with an energy gap of 0.41 eV, while the isos tructural Ru2Ge3 has a competitive indirect-direct character of the band ga p of about 0.31 eV. (C) 2000 Elsevier Science B.V. All rights reserved.