| Title |
The Formation and Phase Transition of fcc Cu Nanocrystallite in Fe99Cu1 Alloy Observed Fluorescence XAFS |
| Abstract |
The Fe_(99)Cu₁ alloy was prepared by the arc melting and annealed at 743 and 823K during the various annealing time. The local structure change around Cu atoms was observed using the fluorescence XAFS because of dilute Cu atoms. In initial stage, the Fourier transform of Cu K-edge XAFS spectra still retain the bcc structure because Cu is substantial in the bcc α-Fe matrix. At the intermediate annealing at 743 and 823K the Fourier transform of Cu K-edge XAFS spectra indicates a distribution of bcc and fcc Cu precipitate dominated by bcc structure. Continued annealing to 700 and 550h at 743 and 823K results in a further decrease in the amplitude of all the peaks in the Fourier transforms of the Cu K-edge spectra. The Fourier transforms more closely resemble those typical of a fcc structure than a bcc structure. This paper proves that fluorescence X-ray absorption spectroscopy can be successfully used to probe the local structure of highly diluted atoms in metallic alloy. |