Optical Properties of Cr–Mn and Cr–V Alloys

The optical reflectance of chromium alloys with up to 10 at.% manganese or 50 at.% vanadium was measured at room temperature for photon energies from 0.475 to 2.24 eV. The Cr–Mn alloy system shows a very slight shift of the chromium absorption edge to higher photon energies, whereas the addition of vanadium shifts the absorption edge to lower photon energies. For the alloy with 10 at.% V, the edge disappears to values below the measured photon energy range. The direction of the shift of the absorption edge can be explained qualitatively in a rigid band model with transitions from the t2g band to the Fermi level. This model was previously proposed to explain optical reflection data of chromium-iron alloys.