Interband absorption of vanadium studied by probing the size-dependent change in energy bands of vanadium particles

For interband absorption with peak at about 2.5-3.0 eV of vanadium, the contribution of the transition from the Fermi level in the region near state Σ 1 to state Σ 4 has been investigated experimentally. The contribution was proposed by Romaniello [ Phys. Rev. B 73 , 075115 ( 2006 )] . When the size of vanadium particles was decreased, the interband absorption weakened remarkably. Considering the raising of the position of state Σ 1 with energy-band broadening due to lattice contraction, the remarkable weakening can qualitatively be ascribed to the ceasing of the transition mentioned above. This confirms the contribution.