TETRAHEDRAL COVALENT RADII OF MN, FE, CO AND NI ESTIMATED FROM EXTENDED X-RAY-ABSORPTION FINE-STRUCTURE STUDIES

The bond radius of an atom in a solid is an important parameter since it remains simply correlated with the bond length in a local coordinat ion of the particular crystal structure. The tetrahedral covalent radi i of Mn, Fe, Co and Ni were estimated from the measurements of their K -edge extended X-ray absorption fine structure in Zn1-xMxS (M = Mn, Fe , Co, Ni) alloys. Analysis of these data provided us with the bond len gths of both cationic species (Zn and M) with sulphur. The advantage o f the common anion and the knowledge of the tetrahedral radius of Zn e nabled us to derive the tetrahedral covalent radii of the transition m etals studied. (C) 1998 Elsevier Science B.V.