W. Henrion et al., OPTICAL CHARACTERIZATION OF RU2SI3 BY SPECTROSCOPIC ELLIPSOMETRY, UV-VIS-NIR SPECTROSCOPY AND BAND-STRUCTURE CALCULATIONS, Thin solid films, 313, 1998, pp. 218-221
The first results of optical interband investigations are reported for
semiconducting Ru2Si3 from the near infrared up to 5 eV and compared
with those of a Ru metal. The single-phase Ru2Si3 layers were prepared
by metal deposition onto silicon substrates and annealing in forming
gas atmosphere. The optical spectra have been obtained by ellipsometry
and reflectivity measurements. From the optical investigations, the r
eal and imaginary parts of the dielectric function as well as the abso
rption coefficient and the refractive index have been derived. The Ru
spectra show typical metallic behaviour, i.e. a Drude-like shape in th
e IR and interband features at higher energy. The spectra for Ru2Si3 e
xhibit semiconducting character with dominant interband features appro
ximately at 2 and 5 eV and a relative minimum in the joint density of
interband states at 3.5 eV. These spectra are compared with theoretica
l calculations of the optical properties which have been carried out u
sing the LMTO-ASA method. Excellent agreement has been found between t
heory and experiment for the spectral variation in the optical constan
ts. (C) 1998 Elsevier Science S.A.