材料期刊网

The fine structure of mechanically alloyed BCC Fe80Cu20 solid solution has been studied by X-ray diffraction (XRD), Mossbauer spectroscopy and the extended X-ray absorption fine structure (EXAFS) technique. The appearance of Mossbauer spectrum with a broad hyperfine magnetic field distribution demonstrates that the alloying is at an atomic level and complex forms of coordination exist in the solution. EXAFS results further prove the atomic alloying from the clear observation of Cu atoms taking on BCC coordination in the solution. Furthermore, a reduction in the nearest-neighbor coordination number of a center Cu atom but not for a center Fe atom due to surface effect and structure defects indicates the composition nonuniformity that Cu atoms are rich at interface and Fe atoms are slightly rich in the core of a BCC nanocrystal.