Optical properties of Ti, Zr, and Hf from 0.15 to 30 eV

Abstract

The absorptivity or reflectivity of polycrystalline samples of Ti, Zr, and Hf was measured from 0.15 to \ensuremath{\sim}30 eV. The data were Kramers-Kronig analyzed to determine the dielectric functions. Between \ensuremath{\sim}0.2 and \ensuremath{\sim}7 eV, each metal showed five structures in the absorptivity and ${\ensuremath{\epsilon}}_{2}$. These were interpreted as interband transitions within the $d$ bands. The ${\ensuremath{\epsilon}}_{2}$ spectra had minima near 7 eV similar to that observed in the bcc transition metals. Additional structures at higher energy could be related to transitions involving highlying bands and the core levels. The electron-energy-loss functions were calculated and discussed in terms of volume and surface plasmons. These metals, like the other transition metals studied, exhibited two volume and two surface plasmons.