LOCAL ELECTRONIC-STRUCTURE OF ZNS AND ZNSE DOPED BY MN, FE, CO, AND NI FROM X-RAY-ABSORPTION NEAR-EDGE STRUCTURE STUDIES

Systematic studies of x-ray-absorption near-edge structure (XANES) at the K edge of cations and anions in ZnS, ZnSe, and ZnMS and ZnMSe comp ounds, with M being a transition metal (Mn, Fe, Co, Ni), were performe d. Our investigations have shown, in agreement with earlier literature results of multiple-scattering theory, that the distribution of unocc upied p-like states around cation atoms is mainly determined by the ty pe of anion and does not depend significantly on the M concentration. Three peak structures can be found in the cation K-edge XANES of the s ulphides, whereas a two-peak structure is observed in selenides. The e ffective charge transfer for the M cation was estimated within 2-2.5e, from measured chemical shifts of the respective K edges. Additionally , direct evidence of hybridization between the states of M and p state s of S was found from S K-edge XANES studies. The empirical correlatio n between the shape of M K edges and the solubility limit of M in the investigated solid matrices was revealed.