-Al13Co4, a new quasicrystal approximant

Experimental reinvestigation of Al–Co phase diagram in vicinity of Al13Co4 family of phases

“…Phases Al 5 Co 2 , Z-Al 3 Co, M-Al 13 Co 4 , and O 0 -Al 13 Co 4 were also found in experimental samples forming single-phase microstructures ( Table 2). These samples were used to obtain single-phase XRD patterns better comparable with the available theoretical models [19,24,28,31]. In Fig.…”

“…The O 0 -Al 13 Co 4 phase is a quasicrystalline approximant from the Al 13 Co 4 family with the structure close related to O-Al 13 Co 4 and M-Al 13 Co 4 . The crystallographic description of this phase was proposed recently by Fleischer et al [19], however it was not included in the phase diagram till now. In the present high-temperature experiment OAl 13 Co 4 was not identified in any of the experimental samples The microstructure corresponding to the Y-Al 13 Co 4 area was found as morphologically heterogeneous (Fig.…”

“…Because of differences in labelling of phases Al 3 Co and Al 13 Co 4 (h) a compromise denotation was used in this paper, Z-Al 3 Co and Y-Al 13 Co 4 , respectively. Crystallographic data of all the above intermediate phases and the O 0 -Al 13 Co 4 phase described recently by Fleischer et al [19] are summarized in Table 1 [10,12e14,19e35].…”

Reinvestigation of the Ce–Co–Al ternary system: Isothermal section at 973K

“…At higher Al content, the two binaries Co 2 Al 5 and Co 2 Al 9 are well characterized. Between these latter phases, a complex situation exists with the superimposition of different structurally related orthorhombic and monoclinic quasicrystalline phases with compositions close to Al 13 Co 4 [28][29][30][31][32]. Their differentiation usually requires the use of transmission electron microscopy and not all their crystallographic data (such as atomic positions) are available in literature.…”

“…The lack of adapted equipment and of atomic data in the literature (e.g. the atomic positions of e-Al 3 Co [30] or o 0 -Al 13 Co 4 [32] are missing) makes it difficult to distinguish between the different structurally Table 2 Homogeneity ranges of the identified solid solutions at 973 K in the Ce-Co-Al system.…”