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Structural, Electronic and Optical Properties of Ru 2 Si 3 , Ru 2 Ge 3 , Os 2 Si 3 and Os 2 Ge 3
Author(s) -
Migas D.B.,
Miglio L.,
Shaposhnikov V.L.,
Borisenko V.E.
Publication year - 2002
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/1521-3951(200205)231:1<171::aid-pssb171>3.0.co;2-0
Subject(s) - pseudopotential , tetragonal crystal system , orthorhombic crystal system , germanide , condensed matter physics , band gap , materials science , electronic band structure , dipole , indium , electronic structure , phase (matter) , chemistry , crystallography , optoelectronics , physics , germanium , crystal structure , silicon , organic chemistry
We have performed a comparative study of structural, electronic and optical properties of Ru 2 Si 3 , Ru 2 Ge 3 , Os 2 Si 3 and Os 2 Ge 3 by means of ultrasoft pseudopotential and full‐potential linearized augmented plane wave methods. The estimated difference in the cohesion energy between the low‐temperature orthorhombic phase and the high temperature tetragonal one for all these compounds indicates that the former phase is lower in energy with respect to the latter one. All materials in the orthorhombic structure are found to be direct band‐gap semiconductors, still some of them in the tetragonal structure display an indirect nature (Os 2 Si 3 ) or a competitive direct–indirect character (Ru 2 Ge 3 ) of the gap. Optical properties are discussed by analyzing the imaginary part of the dielectric function and the dipole matrix elements corresponding to different interband transitions indicating for osmium silicide and germanide the presence of low‐energy transitions with an appreciable value of the oscillator strength.