Title: X-ray photoelectron spectra and electronic structure of quasi-one-dimensional SbSeI crystals
Author(s):

	J.Grigas (Faculty of Physics, Vilnius University, Sauletekio 9/3, LT--10222 Vilnius, Lithuania) ,
	E.Talik (Institute of Physics, Silesian University,Universytetska 4, 40--007 Katowice, Poland) ,
	M.Adamiec (Institute of Physics, Silesian University,Universytetska 4, 40--007 Katowice, Poland) ,
	V.Lazauskas (Institute ofTheor. Phys. and Astronomy, Vilnius University, Gostauto 12,LT--01108 Vilnius, Lithuania)

The paper presents the X-ray photoelectron spectra (XPS) of the valence band (VB) and of the principal core levels from the (110) and (001) crystal surfaces for the quasi-one-dimensional high permittivity SbSeI single crystal isostructural to ferroelectric SbSI. The XPS were measured with monochromatized Al Ka radiation in the energy range of 0-1400 eV at room temperature. The VB is located from 1.6 to 20 eV below the Fermi level. Experimental energies of the VB and core levels are compared with the results of theoretical ab initio calculations of the molecular model of the SbSeI crystal. The electronic structure of the VB is revealed. Shifts in the core-level binding energies of surface atoms relative to bulk ones, which show a dependency on surface crystallography, have been observed. The chemical shifts of the core levels (CL) in the SbSeI crystal for the Sb, I and Se states are obtained.

Key words: SbSeI, electronic structure, XPS
PACS: 79.60.-i, 82.80.Pv, 87.64.Lg