Parameters of a Complex Structure of Optical Functions of Dimagnesium Stannide

The spectra of sixteen optical functions of Mg 2 Sn crystal are determined at 77 K in the range 1–11 eV. The calculations were performed using known experimental reflection spectra R(E), software packages created on the basis of the Kramers–Kronig relations, and analytical formulas for the communication between optical functions. Their main peculiarities and general regularities have been established. The integral spectra of the imaginary part of the dielectric constant ε 2 (E) are decomposed into elementary components in the range from 2 to 5.5 eV using an improved nonparametric method of combined Argand diagrams taking into account the effective number of valence electrons participating in the formation of individual bands. The energies of maxima and the strengths of oscillators of elementary components of the transition bands are determined and their assumed nature and localization are proposed on the basis of the data of well-known theoretical calculations.