Practical Electron Microscopy and Database

Chapter/Index: Introduction | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Appendix

Dodecagonal Quasicrystal

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