open access

https://hdl.handle.net/2115/61053

Dodecagonal quasicrystal in Mn-based quaternary alloys containing Cr, Ni and Si

英語

dodecagonal

2015-04-04

Taylor & Francis

Philosophical magazine letters

95(4)

229-236

A dodecagonal quasicrystal showing 12-fold symmetry forms in Mn-rich quaternary alloys containing 5.5 or 7.5at.% Cr, 5.0at.% Ni and 17.5at.% Si. After annealing at 700 degrees C for 130h, the quasicrystal precipitated in a matrix of beta-Mn-type crystalline phase. The shape of the quasicrystal is needle-like having a length of several tens of micrometres. Electron diffraction as well as powder X-ray diffraction experiments has revealed the following characteristics of the quasicrystal: diffraction symmetry 12/mmm, the presence of systematic extinction for h(1)h(2)h(2)h(1)h(5)-type reflections with odd h(5) index, and then five-dimensional space group P12(6)/mmc. Indexing of the reflections indicated that the dimension of the common edge in the equilateral triangle-square tiling is 4.560 angstrom, and the periodicity is 4.626 angstrom along the 12-fold axis. This is the first example of the dodecagonal quasicrystal synthesized by ordinary metallurgical method in 3-d transition-metal alloys.

学術雑誌論文

Submitted Manuscript Under Review

This is an Accepted Manuscript of an article published by Taylor & Francis in Philosophical Magazine Letters on 08 May 2015, available online: http://www.tandfonline.com/10.1080/09500839.2015.1038332

0950-0839