Structure Refinement of the Icosahedral AlPdMn Quasicrystal Using Quantitative CBED  

作　　者：YUFeng-meit FANGAi-hua ZOUHua-min WANGRen-hui DUANXiao-feng 

机构地区：[1]SchoolofPhysicsandTechnology,WuhanUniversity,Wuhan430072,Hubei,China [2]SchoolofPhysicsandTechnology,WuhanUniversity,Wuhan430072,Hubei,China／／CenterforElectronMicroscopy,WuhanUniversity,Wuhan430072,Hubei,China [3]BeijingLaboratoryofElectronMicroscopy,InstituteofPhysicsandCenterforCondensedMatterPhysics,ChineseAcademyofSciences,Beijing100080,China

出　　处：《Wuhan University Journal of Natural Sciences》2005年第2期393-397,共5页武汉大学学报（自然科学英文版）

基　　金：Supported by the National Natural Science Foundation of China (59871034)

摘　　要：The atomic structure of the perfect AlPdMn icosahedral phase has been studied on a single crystal specimen by quantitative convergent beam electron diffraction (QCBED) technique in combination with describing the shape of atomic surface by symmetry\|adapted series of surface harmonics. The spherical model was used as the starting model for the refinement. By fitting the calculated electron diffraction intensities to the experimental line scan profile, the coefficients in the surface harmonics expansion of the boundaries of atomic surface are refined. The refined parameters show that the fluctuations of the external boundary of atomic surface for Pd at n 0 can be as large as 0.2 nm. The boundaries of atomic surfaces for Mn show little fluctuation. In the present model, the number of unphysically short interatomic distances is significantly reduced in comparison with the spherical model.The atomic structure of the perfect AlPdMn icosahedral phase has been studied on a single crystal specimen by quantitative convergent beam electron diffraction (QCBED) technique in combination with describing the shape of atomic surface by symmetry\|adapted series of surface harmonics. The spherical model was used as the starting model for the refinement. By fitting the calculated electron diffraction intensities to the experimental line scan profile, the coefficients in the surface harmonics expansion of the boundaries of atomic surface are refined. The refined parameters show that the fluctuations of the external boundary of atomic surface for Pd at n 0 can be as large as 0.2 nm. The boundaries of atomic surfaces for Mn show little fluctuation. In the present model, the number of unphysically short interatomic distances is significantly reduced in comparison with the spherical model.

关 键 词：QUASICRYSTAL quantitative convergent beam electron diffraction (QCBED) i  \|AlPdMn 

分 类 号：O753.3[理学—晶体学]