Interband absorption and its relation to the electronic structure of Co-Cr solid solutions

• Veröffentlicht in: Semiconductor Physics Quantum Electronics & Optoelectronics
• Datum: 2013
• ISSN: 1560-8034
• Hauptverfasser: Bondar, V.M., Stashchuk, V.S., Polianska, O.P., Kudin, V.G., Statsenko, A.O.
• Format: Artikel
• Sprache: Englisch
• Veröffentlicht: Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України 2013
• Online Zugang: https://nasplib.isofts.kiev.ua/handle/123456789/117666
• Назва журналу: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Zitieren: Interband absorption and its relation
 to the electronic structure of Co-Cr solid solutions / V.M. Bondar, V.S. Stashchuk, O.P. Polianska, V.G. Kudin, A.O. Statsenko // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2013. — Т. 16, № 1. — С. 76-79. — Бібліогр.: 14 назв. — англ.

The refraction n and absorption χ indices of paramagnetic Сo-Cr alloys with
 10, 20 and 35% chromium concentrations were measured within the spectral range 0.23
 to 2.8 µm (0.44…5.36 eV) at room temperature by spectral ellipsometric methods. Based
 on these data, the dielectric permittivity ε, optical conductivity σ and reflection
 coefficient R at normal incidence were calculated. The dispersion of optical conductivity
 σ(hν) and dispersion curves of residual optical conductivity σ(hν) = σ(hν) – (1 – c) σCo(hν) were analyzed in detail (c – Cr impurity concentration, σCo(hν) – optical
 conductivity of Co solvent). It has been ascertained that new impurity bands are formed
 in the electronic spectrum of Co solvent when Cr impurities are added, which are
 responsible for the extra absorption in Сo-Cr alloys. The localization of impurity energy
 levels in Co-Cr alloys at 1.8…2.0 eV above the Fermi level has been suggested.