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Structure of Ca13Cd76 : A novel approximant to the MCd5.7 Quasicrystals (M = Ca, Yb)

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.

Incommensurately modulated Nowotny chimney-ladder phases : Cr1-xMoxGe∼1.75 with x = 0.65 and 0.84

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

Computer modeling and description of nonstoichiometric apatites Cd5-η/2(VO4)3I1-η and Cd5-η/2(PO4)3Br1-η as modified chimney-ladder structures with ladder-ladder and chimney-ladder coupling

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

Gallium and indium under high pressure

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.

Single crystsl refinement of the incommensurately modulated Mn0.55Ta0.45O1.7, an oxygen deficient fluorite type compound

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

Reassessing the compound CeCd6 : the structure of Ce6Cd37

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

On the question of commensurability - The Nowotny chimney-ladder structures revisited

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

Incommensurately modulated cadmium apatites

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

Electrical resistivity of one-dimensional quasiperiodic η8-Cu5Sn4

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

Bioadsorbents of heavy metals from coal mines area in Mozambique

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

User involvement in housing recovery : Cases from Haiyan affected areas in the Philippines

The aim of this study is to develop a better understanding of the relation between housing recovery and user involvement from a capability perspective. The thesis studies housing recovery in areas affected by typhoon Haiyan, which struck the Philippines on 8th November 2013. The focus is on three perspectives: a) approaches to housing reconstruction, b) explanation for unexpected housing outcomes,

Charge transport in III-V narrow bandgap semiconductor nanowires

This thesis describes charge transport in III-V narrow bandgap semiconductor nanowires. We are particularly interested in quantum transport in InSb, InAs and InP-InAs core-shell nanowires. According to the type of transport mechanism dominating in the devices, this thesis can be divided into four parts.In the first part of this thesis, we investigated the temperature dependent transport properties

Bortglömda utgrävningar grävs fram : Bronsåldersgravarna i Pangs hög och Hässlehögen

Re-excavations of forgotten archaeological material are more relevant than ever. What is not ordered published or digitized risks to become invisible in storages and archaeological research. With new investigations of archaeological contexts and osteological material the article updates our knowledge of Late Bronze Age burials in North-Western Skåne, Sweden.