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

The absorptivity or reflectivity of polycrystalline samples of Ti, Zr, and Hf was measured from 0.15 to ∼30 eV. The data were Kramers-Kronig analyzed to determine the dielectric functions. Between ∼0.2 and ∼7 eV, each metal showed five structures in the absorptivity and ${\epsilon }_2$. These were interpreted as interband transitions within the $d$ bands. The ${\epsilon }_2$ 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.