Optical properties of iron alloys with heavy rare-earth elements

Spectral-ellipsometric measurements by the Beatty method were made in the region from 1 eV to 4 eV at temperatures of 100, 293, and 700 K to determine the relation between the distinctive features of the optical absorption spectrum and the principal parameters of the electron energy spectrum in iron alloys with rare-earth elements. The fundamental bands of interband optical absorption of Fe₂-R alloys (R=Gd, Ho, Er) in the region 2.8–3.1 eV are formed by indirect transitions from d-like states, which are genetically bound to 3d–5d electrons of the transition metal and the rare-earth metal, in a state above the Fermi level.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 64–67, December, 1988.We thank our senior research colleague V. A. Domyshev for supplying the samples and carrying out the x-ray structure analysis.