X-RAY-EMISSION SPECTRA AND VALENCE STATE OF SULFUR-ATOMS OF YBA2[(CUO)(1-X)(NIS)(X)](3)O-4-DELTA

SK alpha(1,2) and SK beta(1) fluorescence x-ray emission spectra of YB a2[CuO1-x(NiS)(x)]O-3(4-delta) (x = 0.01; 0.03) are investigated. Acco rding to analysis of their energy position and fine structure one can conclude that sulphur atoms enter the lattice of Y123 compounds and fo rm oxyanion groups. The oxidation state of S atoms in these compounds depends on their concentration and varies from 4+ to 6+.