EXAFS STUDY OF THE SHORT RANGE STRUCTURE OF NANOCRYSTALLINE BCC-Fe80Cu20 SOLID SOLUTION
来源期刊:Acta Metallurgica Sinica2002年第3期
论文作者:G.M.Wang X.J.Bai T.C.Kuang S.Q.Wei Y.Z.Yang
Key words:mechanical alloying; EXAFS; Fe80Cu20 alloy; nanocrystalline solid solution;
Abstract: The structure of bcc-Fe80 Cu2o solid solution produced by mechanical alloying of theelemental bcc-Fe and fcc-Cu powders has been studied using X-ray diffraction and theextended X-ray absorption fine structure (EXAFS) techniques. The disappearance ofelemental Fe and Cu X-ray diffraction (XRD) peaks and the presence of bcc structuralXRD peaks illustrate the formation of a nanocrystalline single-phase bcc-Fe80 Gu20solid solution. From the EXAFS results, the clear observation of Cu atoms taking onbcc coordination in the solid solution and Fe atoms remaining bcc structure furtherverifies the reality of atomic alloying between Fe and Cu atoms and the lattice changeof Cu from fcc to bcc. However, the supersaturated bcc solid solution is not chemicallyuniform, i.e., some regions are rich in Fe atoms and other regions rich in Cu atoms.
G.M.Wang1,X.J.Bai2,T.C.Kuang2,S.Q.Wei1,Y.Z.Yang2
(1.Center of Structure Analysis, University of Science and Technology of China, Hefei 230026, China;
2.Faculty of Materials and Energy, Guangdong University of Technology, Guangzhou 510090, China)
Abstract:The structure of bcc-Fe80 Cu2o solid solution produced by mechanical alloying of theelemental bcc-Fe and fcc-Cu powders has been studied using X-ray diffraction and theextended X-ray absorption fine structure (EXAFS) techniques. The disappearance ofelemental Fe and Cu X-ray diffraction (XRD) peaks and the presence of bcc structuralXRD peaks illustrate the formation of a nanocrystalline single-phase bcc-Fe80 Gu20solid solution. From the EXAFS results, the clear observation of Cu atoms taking onbcc coordination in the solid solution and Fe atoms remaining bcc structure furtherverifies the reality of atomic alloying between Fe and Cu atoms and the lattice changeof Cu from fcc to bcc. However, the supersaturated bcc solid solution is not chemicallyuniform, i.e., some regions are rich in Fe atoms and other regions rich in Cu atoms.
Key words:mechanical alloying; EXAFS; Fe80Cu20 alloy; nanocrystalline solid solution;
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