The Contribution to Dielectric Constant from Interband Transition Metals

Abstract

The observed dielectric constants of silver show clearly a contribution from the interband transition. Making use of the same values for various parameters as in a previous analysis for optical absorptions, analysis of the dielectric constants is made on the basis of the mechanism of direct transition. It is found that the mechanism of the direct transition from the d-band to the conduction band under the calculated band structure is able to explain consistently the optical absorption and the dielectric constant. By calculating the energy decrease for an excited state of the system resulting from the fact that conduction electrons screen a d-hole, it is shown that the discrepancy in the gap energy between our band structure taken consistently with the optical data and the band structure calculated by Segall can be explained by the many body effect. For sodium, it is shown that the contribution to the dielectric constant from the excitation of conduction electrons into the nearest higher band is negligibly...