Electron microscopy
 
Dodecagonal Quasicrystal
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Figure 1452 shows the 2-D (two-dimensional) quasiperiodic dodecagonal Stampfli-type tiling with diffraction symmetry 12mm.

Octagonal Quasicrystal
Octagonal Quasicrystal
(a)
(b)
Figure 1452. 2-D quasiperiodic dodecagonal Stampfli-type tiling with diffraction symmetry 12mm: (a) Black and white formats and (b) Same pattern as (a) but with a highlighted portion. The corresponding four basis vectors a1, a2, a3 and a4 are shown and the linear combinations of r = Σiuiai across all lattice points.

Dodecagonal quasicrystal structures normally are in metastable phases. Examples of such structures are Cr-Ni (e.g. Cr71Ni29), V-Ni (e.g. V3Ni2) and V-Ni-Si alloys. The translational period along the 12-fold axis is ~0.45 nm.

 

 

 

 

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