EXAFS study of ball-milled elemental nanocrystalline powders

Nanocrystalline elemental powders of Cr, Fe, Ni, and Cu were prepared by high-energy ball milling and studied using EXAFS spectroscopy. Data were acquired in total electron yield to avoid thickness effects, and a detailed analysis was performed to obtain structural parameters. While significant amplitude reduction was observed in the EXAFS signals of the ball-milled powders, reduction in first neighbor coordination number based on curve-fitting was limited to ≤ 15%. The results are consistent with the presence of nanocrystalline structures and structural defects induced by the milling process.