The Local Structure of Amorphous Gd80Si12B8

We report the local structure of an amorphous alloy Gd80Si12B8 determined from an extended x-ray absorption fine structure (EXAFS) measurements near the Gd L-III edge. Analysis is made using an asymmetric pair distribution function. The distances from the Gd atom are 2.55 Angstrom to B, 2.96 Angstrom to Si and 3.50 Angstrom to Gd. The interatomic separation between Gd atoms is rather consistent with one for 12-coordinated metals, while the distances of Gd-B and Gd-Si are close to ones estimated from radii of atoms in tetrahedral covalent bonds rather than metallic radii. A central Gd atom has 11.4 nearest neighbors which consist of 0.9 B, 1.4 Si and 9.1 Gd atoms.