Luzhnyi I. Electronic structure and optical properties of Tl4ВХ6 (В = Cd, Hg, Pb; X = Cl, Br, I) compounds

In the thesis the electronic structure and optical properties of a number of halides of Tl4BX6-type (B = Hg, Cd, Pb; X = Cl, Br, I) are investigated. In particular, the XPS spectra of the core-level and valence electrons of the Tl4BX6 compounds at room temperature were derived; the energy distribution of valence I p-states and Br p-states of halides at isomorphic substitutions of atoms is studied by X-ray emission spectroscopy based on the analysis of X-ray emission I Lγ4– and Br K2– bands, respectively. Theoretical “first principles calculations" of the density of electronic states and the band structure of Tl4BX6 compounds (B = Hg, Cd, Pb; X = Cl, Br, I) are performed. The basic optical constants (absorption coefficient α(ω), real and imaginary parts of the dielectric function (ε1(ω) and ε2(ω)), refractive index n(ω), extinction coefficient k(ω), optical reflection coefficient R(ω), energy loss spectrum L(ω) are calculated for the Tl4HgBr6compound. Raman spectra were studied for the halides under consideration. Keywords: halides, X-ray photoelectron spectroscopy, X-ray emission spectroscopy, electronic structure, optical properties, band structure calculations.