Chinese Acad Sci, Inst Met Res, State Key Lab Rapidly Solidified Nonequilibium Al, Shenyang 110015, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Synchrotron Radiat Lab, Beijing 100039, Peoples R China
Extended x-ray-absorption fine-structure measurements (EXAFS) were performed on nanocrystalline (nc) elemental Se samples with grain sizes ranging from 13 to 60 nm. Accompanied with the previous study, we concluded that, with the refinement in nc Se, the intrachain structure (the bond length, the coordination number) is unchanged while the interchain spacing is enlarged. The grain boundary in the nc Se is found to be in a low-energy configuration that is different from the disordered ''gaslike" grain boundary structure. [S0163-1829(99)01014-0].