K -emission spectra of Zn, ZnS, and ZnSe within dipole and quadrupole approximations

The present work deals with the x-ray $K{\ensuremath{\beta}}_{2,5}$-emission bands and the electronic structures of Zn metal as well as ZnS and ZnSe compounds. The above-mentioned compounds were chosen the subject of the investigation because they are ideal materials to study the $3d\ensuremath{-}4p$ hybridization since the Zn $d$ band is about 10 eV below the Fermi level and therefore the $K{\ensuremath{\beta}}_{2}$ and $K{\ensuremath{\beta}}_{5}$ spectra are quite well separated from each other. The $K{\ensuremath{\beta}}_{5}$ spectra of ZnS and ZnSe compounds are found to be largely caused by the quadrupole radiation. The electronic structures of the investigated materials are obtained by using the linear muffin-tin orbital method. The calculations show that for cubic crystals the quadrupole spectra can have a strong polarization dependence although the dipole spectra are independent of polarization. The theoretical spectra of the investigated materials are treated in the framework of the full band-structure representation.