Extended x-ray-absorption fine-structure and perturbed-angular-correlation study of impurity clustering in dilute nickel-alloys
Decoster, P × Swinnen, B Milants, K Rots, Michel Larosa, S Pennisi, Ar Faraci, G #
American physical soc
Physical Review B vol:50 issue:14 pages:9752-9758
We report on an experimental study of indium and niobium impurity distributions in NiNbIn dilute alloys by combining the perturbed-angular-correlation (PAC) technique with extended x-ray-absorption fine-structure (EXAFS) measurements on both the indium and niobium K edges at room temperature. Our EXAFS results show that around the indium or niobium central atom, the first-shell coordination number is strongly reduced with respect to a pure nickel environment. Whereas niobium is found in the first shell around niobium in small cluster configurations, indium is found at larger distances from indium indicating a repulsive In-In interaction. No close mixing between these two impurities was detected, confirming the strong In-Nb repulsion. These findings are fully consistent with the conclusions drawn from the data obtained in an earlier as well as the present PAC study.