Comparison of the optical properties of V, Cr and Mn with nondirect transitions calculations

Ellipsometric measurements of the optical properties of bulk specimens of V, Cr and Mn are reported for the photon energy range 0.8 eV to 4 eV and compared with previous work. It is shown that, apart from some small discrepancies in spectral position, the observed structure in the absorption coefficient for each of these metals can be successfully predicted from calculations based on the assumption of nondirect transitions and using the density of states according to recent band calculations. In this way some correlation of optical structure with band structure is achieved. However no firm conclusion can be drawn about whether the predominant transitions are really nondirect or direct.