Fig. 3.

Diffraction patterns. a Lattice parameter a of 1/1AC samples determined from X-ray diffraction method as a function of Al content. Note that a decreases almost linearly with Al content. b Representative X-ray diffraction patterns of the QC, the 2/1AC, and the 1/1AC_G. Note that six integers are needed to index the peak of the QC. c, d Fivefold electron diffraction patterns of the QC. Magnified image (d) shows deviation from the perfect regular pentagon for weaker reflections. e Twofold electron diffraction pattern of the QC. f, g Electron diffraction patterns of 2/1 and 1/1AC with the incident beam along each [001] direction