Modulated Structure in Al_<65>Cu_<20>Fe_<15-X>Mn_X Alloys, Studied by Transmission Electron Microscopy
Features of crystal structures of Al<SUB>65</SUB>Cu<SUB>20</SUB>Fe<SUB>15−X</SUB>Mn<SUB>X</SUB> alloys have been investigated by transmission electron microscopy. Electron diffraction patterns obtained experimentally show that some alloys exhibit similar diffraction patterns to those of the decagonal quasicrystal, in addition to those taken from the icosahedral quasicrystal as well as the Al<SUB>3</SUB>Mn and Al<SUB>13</SUB>Fe<SUB>4</SUB> crystalline approximants. That is, there are both diffraction patterns showing a crystal period of 1.2 nm along one direction and a pseudo-tenfold one with an electron incidence parallel to it. From high resolution images taken in the present works, it was also found that these patterns originate from a single-state region. These results clearly imply that a structure characterized by these patterns can be identified as a two-dimensional modulated structure, which should be distinct from not only the icosahedral and decagonal quasicrystals but also the crystalline approximants.
- Materials transactions, JIM
Materials transactions, JIM 37(5), 1214-1218, 1996-05