Structural relationship between an icosahedral phase and a 1/1 cubic crystalline approximant in an Al–Li–Cu alloy system, studied by atomic-scale observations of electron microscopy

• Published in: Journal of alloys and compounds Vol. 342; no. 1; pp. 120 - 125
• Main Authors: Konno, T.J, Ohsuna, T, Hiraga, K
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Lausanne Elsevier B.V 14-08-2002; Elsevier
• Subjects: Al–Li–Cu system; Applied sciences; Condensed matter: structure, mechanical and thermal properties; Crystal structure and symmetry; Crystalline approximant phase; Crystalline quasicrystal; Exact sciences and technology; Metals. Metallurgy; Physics; Quasicrystals; Scanning and transmission electron microscopy; Semi-periodic solids; Structure of solids and liquids; crystallography; Crystalline approximant phase; Scanning and transmission electron microscopy; Crystal structure and symmetry; Crystalline quasicrystal; Al–Li–Cu system; Cubic lattices; Stacking faults; Aluminium base alloys; Electron diffraction; Ternary alloys; Experimental study; Quasicrystals; Solid structure; Lithium alloys; Icosahedral phase; Transmission electron microscopy; Approximant; Copper alloys; Atomic clusters
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/S0925-8388(02)00155-X

We observed cubic R-phase and icosahedral I-phases in the Al–Li–Cu system by high-resolution transmission electron microscopy (HREM). The images of both the phases taken from three-fold axes showed the presence of the same kind of atom clusters, which are most likely to be the small triacontahedra. The R-phase was found to contain stacking faults along the {110} plane. This stacking fault is created by the insertion of extra atom units, which destroys the symmetry of the lattice, yet the symmetrical configuration of the facing clusters is well preserved.