Electronic properties of isostructural ruthenium and osmium silicides and germanides

Abstract

Electronic band structure calculations of Nowotny ''chimney-ladder'' isostructural ruthenium and osmium silicides and related germanides have been performed by the linear muffin-tin orbital method within the local density approximation. Both silicides have been found to be direct gap semiconductors with energy gaps of 0.41 and 0.95 eV in Ru 2 Si 3 and Os 2 Si 3 , while the band gaps in the germanides have a competitive indirectdirect character with gaps of about 0.3 and 0.9 eV in Ru 2 Ge 3 and Os 2 Ge 3 , respectively.

Consideration of the validity of the 14 valence electron rule for semiconducting chimney-ladder phase compounds

“…6(a). The BS obtained in the present study has a close resemblance to the previous study [18]. It is characterized by a direct transition at the G point of the Brillouin zone.…”

“…It is characterized by a direct transition at the G point of the Brillouin zone. However, the gap value predicted is 0.49 eV, which is slightly larger than the value of 0.41 eV in the previous study [18]. The experimental value of the energy gap for Ru 2 Si 3 is 0.44 eV [19].…”

“…Its electronic structure calculations have been investigated by the linear muffintin orbital (LMTO) method [17,18]. However, results for Ru 2 Si 3 will be also presented in the present section for comparison.…”

Microstructure and Local Density of States of Ruthenium Silicide on Si(001) Surface

“…This indicates that the electronic state near the interface between the silicide grain and silicon substrate is different from that at the top of the grain. Theoretical calculations of Ru 2 Si 3 indicates that a peak arises from a large density of states at ¹1.0 eV below E F , 11,15) and we assign the peak in Figs. 3(b) and 3(c) to originate from a composition very close to Ru 2 Si 3 .…”

Structure, Stoichiometry, and Properties of the Chimney-Ladder Phases Ru2Ge3+x (0<x<1)

“…In addition, electronic band structure calculations performed for Ru 2 Ge 3 indicate that the electronic states near the Fermi energy have dominant contributions from the Ru d-orbitals (8,9). This suggests that the picture of the interconnected Ru lattice as an electron-crystal containing within it a Ge phonon-glass may be applicable, and that these may be good thermoelectric materials.…”