Optical properties of Ca in the range 2.1-11.5 eV

Abstract

The optical reflectance of Ca in the range 2.1-11.5 eV has been measured. The optical conductivity was obtained from the measurements via a Kramers-Kronig analysis. The optical conductivity in the approximation of constant matrix element and optical surfaces were calculated using a band-structure calculation of Nilsson et al (1973). Fair agreement between the measured and calculated optical conductivity was obtained, thus confirming the alpha = 2/3 exchange parameter used in the band-structure calculation. The optical surfaces in a direct transition model show that the excitations are extended over large parts of the Brillouin zone.