Stacking sequences and symmetry properties of trigonal vacancy-ordered phases (τ phases)

Eric A. Lord, S. Ranganathan, Anandh Subramaniam
2002 Philosophical Magazine A  
The vacancy-ordered phases known as t phases are described and the literature dealing with the observed stacking sequences is reviewed. It is shown that the stacking sequences along the threefold axis can be derived from a projection method involving projection on to an axis of type ‰rrq qŠ. The structure has alternating ®lled and empty lamellae parallel to planes of type ...rrq q). The particular cases in which r and q are consecutive numbers of the Fibonacci sequence can be regarded as
more » ... regarded as rational approximants to a onedimensional quasiperiodic structure. Some mathematical properties of the sequences, and their relationship with the three-dimensional structures, are presented.
doi:10.1080/01418610208239597 fatcat:ib6ivz4ebjanjcmkmovdlq2mfq