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Nanoporous carbons have been prepared through a selective etching reaction, performed by halogenisation of aluminum carbide. The structures obtained can be controlled by varying the chlorination temperature. The unique set of nanocarbons obtained include nanoporous amorphous structures, the nanobarrel structure and a nanographitic structure as chlorination temperatures were increased from 400 °C t
The first known example of a regular face-sharing icosahedra helix is presented in the novel crystal structure of δCo2Zn15, solved and refined from single-crystal X-ray and neutron powder diffraction data. The compound δCo2Zn15 is also the first example of an intermetallic compound crystallizing in the acentric hexagonal space group P62. The parameters from the single crystal refinement are a = 11
The title compound Dy13Zn57, crystallizes in the orthorhombic space group Pnma (No. 62) with the cell parameters a = 14.060(5), b = 14.260(5) and c = 24.700(3) Å. The structure has formerly been described as Dy13Zn58 with the hexagonal type structure of Gd13Zn58. Single-crystal X-ray diffraction measurements however, show extra reflections breaking the C-centering of the corresponding orthorhombic
The title compound was synthesized according to Andersson Acta Chem. Scand. 18 (1964) 2233. The structure is an incommensurately modulated variation of the UO3 structure, in a (3 + 1)-dimensional super space description isostructural to the composite phases (1 - x)Ta2O5•xWO3 Acta Crystallogr., Sect. B 52 (1996) 223 and Acta Crystallogr., Sect. B 51 (1995) 709. The compound crystallizes in the orth
Cl14Mo6Sn, cubic, Pn3̄ (No. 201), a = 12.952 Å, V = 2172.8 Å3, Z = 4, Rgt(F) = 0.048, wRref(F) = 0.063, T = 293 K.
Two new lithiated phases of V6O13 were formed by carefully tuning the temperature of electrochemical lithiation in a 'coffee-bag' type Li-ion battery at 2.78 V versus Li/Li+. These were studied by single-crystal X-ray diffraction. A phase with the composition Li2/3V6O13 was obtained at 308 K with a unit cell three times the volume of the original V6O13 cell. A single crystal discharged at ambient
We present a combined experimental and theoretical study of the structure and the lattice dynamics in the complex metallic alloy Mg2Zn 11, by means of neutron and x-ray scattering, as well as ab initio and empirical potential calculations. Mg2Zn11 can be seen as an intermediate step in structural complexity between the simple Laves-phase MgZn2 on one side, and the complex 1/1 approximants and quas
The closest cubic approximant to the MCd5.7 (M = Ca, Yb) quasicrystals known so far, namely Ca13Cd76, was obtained by high-temperature reaction of the elements. It exhibits a new type of structure for intermetallic compounds with an unprecedented arrangement of triacontahedral clusters (see structure), which could prove useful in modeling the structures of the MCd5.7 quasicrystals.
The crystal structures of two new ternary, incommensurately modulated phases in the Cr/Mo/Ge system, Cr1-xMoxGe∼1.75 with x = 0.65 and 0.84, have been refined using the same composite approach as for the earlier reported compounds, (Mo/Rh)11Ge18 and (Mo/Rh)13Ge22, from the Mo/Rh/Ge system. The composite model consists of a rather stable diamond-like transition metal substructure and a helical main
Diffraction patterns from apatite-structure compounds Cd5-η/2(TO4)3X1-η with T=P, V and X=Br, I show sheets of diffuse scattering normal to c* at incommensurate l=q (q=1.63 for Cd-V-I apatite and q=1.78 for Cd-P-Br apatite), because the c repeat of the average unit cell is shorter than two X diameters. The equilibrium X..X spacing along c defines the incommensurate periodicity c/q and stoichiometr
BrO12P3Sr5, hexagonal, P63/m (No. 176), a = 9.972(1) Å, c = 7.214(1) Å, V = 621.3 Å3, Z = 2, Rgt(F) = 0.042, wRall(F) = 0.024, T = 293 K. Ba5BrO12P3, hexagonal, P63/m (No. 176), a = 10.342(2) Å, c = 7.673(2) Å, V = 710.7 Å3, Z = 2, Rgt(F) = 0.022, wRall(F) = 0.015, T = 293 K.
A study was carried out to explore the structural competition between the high symmetry fcc and low symmetry bct structure for the IIIA metals Al, Ga, and In. It was found that the competition originates from electronic properties. As a result, the high pressure behavior of the metals appears reversed to the corresponding-states rule.
A structural investigation of the incommensurately ordered compound Mn0.55Ta0.45O1.7 has been carried out, using single-crystal X-ray diffraction data. The basic structure is related to the fluorite type with a monoclinic distortion. Electron diffraction (ED) patterns for various crystal orientations were used for determination of unit cell, incommensurate modulation vector and superspace group. T
The crystal structure of the phase Ce6Cd37 was determined by single-crystal X-ray diffraction. It is closely related to, and indeed probably identical to, the previously reported compound CeCd6. The compound crystallizes in the centrosymmetric space group Pn3̄ with the unit cell axis 15.808(2) angstrom. The structure may be described by successive shells centered around the origin and the position
A composite approach was used for the structure solution and refinement of two new Nowotny chimney-ladder phases, (Mo/Rh)11Ge18 and (Mo/Rh)13Ge22, found during investigations in the Mo/Rh/Ge system. The descriptions of the phases with conventional models (in I4̄2d (No. 122) with a = 5.885(2) Å, c = 52.62(2) Å for (Mo/Rh)11Ge18 and a = 5.922(1) Å, c = 62.88(4) Å for (Mo/Rh)13Ge22) led to high numbe
Two cadmium apatites, Cd5(PO4)3Br and Cd5(VO4)3I, earlier reported to be halogenide deficient, were prime suspects of being modulated. In this study, incommensurate ordering was found in satellites occurring in planes perpendicular to c*. The structure of Cd5(PO4)3Br was refined from single-crystal X-ray diffraction data in the four-dimensional super space group R:P3̄:(00γ): a = 16.932(2) Å, c = 6
The electrical resistivity, ρ, of one-dimensional quasiperiodic η8-Cu5Sn4 has been studied, and compared with crystalline Cu6Sn5 of identical basic structure (B8) and closely related atomic structure. ρ was measured between 1.5 and 300 K on needle-shaped crystals with their axes along the base lattice c direction, corresponding to the quasiperiodic direction in η8-Cu5Sn4. ρ (4 K) was found to be n
Mozambique is one of the largest coal exporters in Africa. Usually miningactivities generate polluted water that is discharged into the Zambezi river basin in the Moatize area without treatment, increasing the risk both to the local environment and to public health because of this water containing significant amounts of metals and metalloids. At the same time, Mozambique is one of the largest prod
