SPIN-DEPENDENT EXAFS IN DYFE2

The SPEXAFS in DyFe2 powder at the Fe K-edge was measured at 20 K and a high quality spectrum was obtained. The DyFe2 alloy has a crystallin e structure of a C15 Laves phase and the spin moments of Fe ferrimagne tically couple with those of Dy. The pair distributions reflecting the sign of spin moments were derived for the first time by calculating t he F(r) profile as the difference between the absolute value of Fourie r transformed (k3)chi(+)(k) and (k3)chi(-)(k). In F(r), a negative pea k and positive one were obtained at the position of Fe- (2.37 Angstrom ) and Dy-(297 Angstrom) shells, respectively. The results confirm the validity of the present analytical method to obtain the pair distribut ions with the sign of spin moments. It extends the usefulness of SPEXA FS as a tool to study magnetic structures.