Filtyp
β-Zn4Sb3 is an outstanding thermoelectric material mainly due to its extraordinarily low thermal conductivity, which is similar to that of glasses. Recently it was proposed that interstitial Zn atoms are responsible for this peculiar behavior. Here we report on the crystal and electronic stucture of the low-temperature polymorph α-Zn4Sb3. During the reversible phase transition the intricate disord
The novel structure of the δ1 phase in the cobalt-zinc system was determined by single-crystal X-ray diffraction. The structure features fused double icosahedra linked by edge-and face-sharing. The δ1-CoZn7.8 structure is incommensurately modulated along the columnar b direction. The extent of the linear pentagonal antiprismatic intergrowth is limited to a maximum of two overlapping icosahedra bec
Single crystals of LaSeTe2 have been prepared by reaction of the elements in a LiCl/RbCl flux at 970 K for seven days. Satellite reflections observed in diffraction experiments indicate the presence of an incommensurate lattice distortion, which is of the charge-density-wave (CDW) type. The modulated structure has been solved from X-ray data at 173, 293, and 373 K. LaSeTe2 crystallizes in the 3+1-
The copper vanadium oxide bronze Cu2.33-xV4O 11 exhibits a three part composite structure refined on the basis of XRD low-temperature studies. It crystallizes in the triclinic system with the non-centric superspace group X1 and cell parameters a=15.280(3)Å; b 1=3.616(1)Å; c=14.674(3)Å; α=90.0°; β=101.95(3)°; γ=90.0° with a modulation q-vector equal to (0,0.11,0). The three different parts of this
Several of the MCd6 approximants (M=Pr, Nd, Sm, Eu, Gd, Dy, Yb, Y, and Ca) to the MCd5.7 quasicrystals (M=Yb and Ca) have been synthesized and their structures have been refined from single-crystal x-ray-diffraction data; the different types of disorder of the central Cd4 tetrahedra located in the dodecahedral cavities of these closely related compounds have been examined and mutually compared. A
New niobium-based misfit sulfides (Ln1/3Sr2/3S)1.5]1.15 NbS2 (Ln = Sm, Tb) have been synthesized from a mixture of SrS, Ln2S3, Nb(m), and S in evacuated and sealed silica tubes by annealing at 1000 °C for 144 h under a sulfur partial pressure of 49.3 kPa. The compounds have been characterized by EDX analysis, X-ray single crystal and powder diffraction, electron diffraction, and magnetic susceptib
Synthesis, X-rays, TEM and HREM studies of the composition x = 0.25 of the solid solution Sb2W1-xMoxO6 are reported. The phase crystallises in the monoclinic system, space group C2 and the cell parameters of its average structure are a = 11.1296(6) Å, b = 9.8868(9) Å, a = 18.501(2) Å, and β = 96.951(9)°. Mo and W atoms are ordered in the 1/3 ratio. Twining and extended defects have been studied by
A single crystal of the cubic spinel LiMn2O4 was delithiated electrochemically at 4.06 V vs. Li/Li+ to probe the structural source of the inflection point at ca. 4.1 V vs. Li/Li+ in the discharge curve. The phase thus obtained was investigated by single-crystal X-ray diffraction and the structure refined. The structure is closely related to the original cubic structure, but the new space group is
Solid-state synthesis in the Bi-Se system produced both commensurate and incommensurate phases of compositions ranging from Bi2Se3 to Bi4Se3, all crystallising in rhombohedral or trigonal layer structures. The a parameters are very similar for all phases but the c parameters vary irregularly between 10 and 100 Å. A general model for all these phases was developed, using single crystal X-ray diffra
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.
