Interband Absorption in the Coloured Intermetallic Compounds PdIn

Abstract

The refractive, n, and absorption, k, indexes of six intermetallic PdIn compounds are measured in the spectral range of 0.248 to 17 pm by Beattie's polarimetric method, the indium concentration being 42, 44, 46, 48, 50, and 52 atyo. All the compounds are single crystals. It is shown that as the indium concentration increases from 42 to 52 atyo, the interband absorption peaks found a t 0.15 to 0.17, 0.6 to 0.7, 2.2 to 2.65, and 2.6 to 3.2 eV shift towards lower energies, while that at 4.6 eV does not change its position with temperature and indium concentration. Comparison of the high-frequency conductivity ~( w ) dispersion and the energy bands of equiatomic P'-PdIn shows that the interband absorption a t hw < 3 eV is caused by the electronic transitions from the