Optical properties and electronic structure of white tin

The optical properties of a tin single crystal and of a tin film deposited by vacuum evaporation were measured in the energy range from 0.5 to 5.5 eV in dependence on temperature and crystal orientation. The absorption curves differ appreciably for the two polarizations and show many structures which become more pronounced at low temperatures. These structures in the optical absorption are related to regions of the band structure where the bands are nearly parallel. The results show that existing band structure calculations of tin are accurate near the Fermi energy, for energies above and below E F , however, the shape of some of the bands should be corrected.