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A new binary phase, Cu 10 In 7 , was found during the investigation of the η-phase field in the Cu-In system. Single crystals of Cu 10 In 7 were grown from a melt under an inert atmosphere. The compound crystallizes in the monoclinic space group C2/m with cell parameters a ϭ 13.8453(2) Å , b ϭ 11.8462(1) Å , c ϭ 6.7388(1) Å and β ϭ 91.063(1). The structure is based on a unit of 2589 face-sharing octahedra consisting of five Cu 4 In 2 octahedra terminated by Cu 5 In octahedra at both ends. The crystal structure is closely related to the Cu 11 In 9 structure type.

In a systematic study of the binary quasicrystal approximants RE 13 Zn ∼58 (RE=rare earth elements) system, single crystals of Ho 13 Zn 58 have been prepared. It is unique among the family members of the RE 13 Zn ∼58 system, in that it shows a modulated superstructure ordering. Satellite reflections observed in single crystal X-ray diffraction pattern indicate the presence of a one-dimensional lattice distortion. The modulated structure has been solved and refined from X-ray data using the superspace group approach. The Ho 13 Zn 58 structure can be described in the (3+1)-dimensional superspace group Pc2 1 n (0β0)s0s with lattice parameters a=24.6481( 7)Å, b=14.2484(4)Å, c= 14.0153(3)Å and a modulation vector q=(0, 0.741, 0). The crystal structure is closely related to those of the other RE 13 Zn ∼58 compounds, comprising hexagon-shaped tunnels, made up of rare earth centred Zn polyhedra. All atoms in the structure are affected by a displacive modulation but one set of Zn atoms are very strongly affected, and display an almost composite behaviour with regard to the rest of the structure.

The η-phase field of the Cu-In system is unusually rich and shows wealth of phases that are all related to the B8 (NiAs/Ni2In) type. Previous electron diffraction work has revealed extensive super structure ordering; in this study, we report single crystal diffraction experiments on high-quality samples of two of the phases in the system, ht1-Cu 5 In 3 and ht2-Cu 5 In 3 . Both these phases constitute super structures, caused by the ordering of interstitials. The structure ht2-Cu 5 In 3 is a relatively simple structure with a bidimensional modulation but where only first order satellites are visible, indicating incomplete order whereas ht1-Cu 5 In 3 displays many high order satel- [a]

Structure D 2000The Structure of Cu6Sn5-xSbx -Large Effects of Subtle Doping. -Sb-substituted Cu 6 Sn 5 with up to 12% Sn exchanged by Sb is synthesized from the elements (quartz tube, 663 K, 96 h) and its structure is determined by single crystal XRD. It crystallizes in the monoclinic space group P21/c with Z = 4 and exhibits a diffraction pattern very similar to that of η 8 -Cu5Sn4. The inclusion of trace amounts of antimony shifts the region of the thermal stability of η 8 -Cu5Sn4 from 186°C down to room temperature. -(LIDIN*, S.; PIAO, S.-Y.; Z. Anorg. Allg. Chem. 635 (2009) 4-5, 611-613; Dep. Inorg. Chem., Arrhenius Lab., Univ. Stockholm, S-106 91 Stockholm, Swed.; Eng.) -W. Pewestorf 26-002

The number of modulated structures with more than one modulation vector is small, and such structures often pose special problems in solving and refining. This talk will be concentrated on three such cases; The 3+4 dimensionally modulated cubic structure of digenite, the 3+2 dimensionally modulated structure of Cu3In2, the 3+2 dimensionally modulated structure of AuZn3 and the 3+2 dimensionally modulated structure of Se(Sn4)2K10. The three former cases are interesting because they are relatively weakly ordered structures where modelling is straight-forward, but the model itself is less than obvious to understand while the latter case appears highly ordered, but presents formal modelling difficulties. From these and previously known multi dimensional cases it would appear that higher order modulations are very prone to disorder. The image shows the hk0 layer from Se(Sn4)2K10.https://www.eiseverywhere.com/retrieveupload.php?c3VibWlzc2lvbl80NjYxOV8zNTQ2MDMuanBnKmVzZWxlY3Q=