Optical properties of scandium thin films.

A new investigation of the optical properties of scandium is presented. Near-normal-incidence reflectivity measurements were performed from 0.22 to 5.5 eV on polycrystalline thin films evaporated in situ in ultrahigh vacuum. The reflectivity, from 0.22 to 35 eV, of the same samples after they had been exposed to air was also measured. The ultraviolet reflectivity was affected by oxygen contamination and a structure around 21 eV was recognized as due to the surface oxide layer. The structures below 5 eV were assigned to pure scandium metal. The interband part of the dielectric tensor was calculated from the electron energy bands presented by Das and good agreement was found with the experimental curves.