Oxide ion conductors are important materials with a range of technological applications and currently used as electrolytes for solid oxide fuel cells electrolyzer cells. Here we report the crystal structure electrical properties hexagonal perovskite derivative Ba3MoNbO8.5. Ba3MoNbO8.5 crystallizes in hybrid 9R palmierite structures. This is new so far unique that contains disordered distribution (Mo/Nb)O6 octahedra (Mo/Nb)O4 tetrahedra. shows wide stability exhibits predominantly conduction...

Various structural families have been reported to support oxide ion conductivity; among these, perovskite conductors received particular attention. The structure is generally composed of a framework corner-sharing octahedral units. When the units share their faces, hexagonal perovskites are formed. Mixed combinations and face-sharing can give rise variety derivatives. However, ionic conducting properties these materials not well explored. In this feature article, we review most significant...

Rietveld refinements using neutron diffraction data have been used to determine the crystal structure of a series oxygen-deficient barium titanate powders, BaTi IV 1–x Ti III x O 3–x/2 (0<x<0.30). The powders were prepared by reduction stoichiometric, tetragonal BaTiO 3 in vacuum furnace at temperatures above 1300 °C and under an oxygen partial pressure 0.1 mbar. 6H-BaTiO hexagonal perovskite is retained throughout accompanied formation O(1) vacancies h-BaO layers which separate pairs...

Barium titanate (BaTiO 3 ) can be doped with La 3+ ions via partial substitution for Ba 2+ ions; charge balance is maintained by the creation of Ti 4+ vacancies. Samples processed in an atmosphere 1 bar O 2 and a temperature 1350°C are insulating free from electronic defects associated either loss or reduction to . The Curie ( T c decreases approximately linearly as lanthanum content increases and, at same time, increase permittivity (ɛ′) maximum occurs. For composition 1‐ x /4 , where =...

A variable temperature neutron and synchrotron diffraction study have been performed on the giant magnetoresistant oxypnictides LnMnAsO (Ln = La, Nd). The low magnetic structures studied results show a spin reorientation of Mn2+ spins below TN (Nd) for NdMnAsO. rotate from alignment along c to into basal plane Nd3+ moments refine 3.54(4) \mu B 1.93(4) respectively at 2 K. In contrast there is no change in structure with LaMnAsO. There evidence structural transition down K, however...

Solid proton and oxide ion conductors have key applications in several hydrogen-based energy-related technologies. Here, we report on the discovery of significant conductivity palmierite oxides A3V2O8 (A = Sr, Ba), which crystallize with a framework isolated tetrahedral VO4 units. We show that these systems present prevalent ionic conduction, large protonic component under humidified air (tH ∼ 0.6-0.8) high mobility. In particular, Sr3V2O8 is 1.0 × 10-4 S cm-1 at 600 °C, competitive best...

A variable temperature neutron diffraction study of the novel oxide ion conductor Ba3MoNbO8.5 has been performed between 25 and 600 °C. Nonmonotonic behavior cell parameters, bond lengths, angles are observed indicating a structural rearrangement above 300 The oxygen/vacancy distribution changes as increases so that ratio (Mo/Nb)O4 tetrahedra to (Mo/Nb)O6 octahedra upon heating strong correlation ionic conductivity number within average structure is observed. increase in from 300–600 °C most...

The crystal structure of the novel oxide ion conductor Ba₃WNbO_8.5.

The hydrothermal reactions of lead(II) acetate with carboxylic acids gave solids composition [Pb(C4H4O4)] 1 (C4H4O4 = succinate); [Pb6O2(C14H9O3)8] 2 (C14H9O3 benzoylbenzoate), [Pb(C8H4NO4)2(H2O)] 4 (C8H4NO4 2-nitrobenzoate) and [Pb(C8H3N2O6)2(H2O)] 5 (C8H3N2O6 3,5-dinitrobenzoate). reaction lead monoxide trichloroacetic acid in hot wet toluene followed by filtration cooling a solid [Pb3(C2Cl3O2)6(H2O)3] 3. compounds were characterised X-ray single crystal structure determinations. Compounds...

A sizeable negative magnetoresistance (MR) has been observed for oxypnictides LnOMnAs (Ln = La,Nd). MR up to −24% is at 200 K LaOMnAs which unprecedented divalent Mn2+. Both materials are weak ferromagnets with transition temperatures above room temperature.

There has been a resurgence of interest in alpha-tricalcium phosphate (α-TCP), with use cements, polymer composites and bi- tri-phasic calcium bone grafts. The simplest most established method for preparing α-TCP is the solid state reaction monetite (CaHPO4) carbonate at high temperatures, followed by quenching. In this study, effect chemical composition reagents used synthesis on local structure final product reported findings previously pertaining to phase stability are also corroborated....

Colossal magnetoresistance is a rare phenomenon in which the electronic resistivity of material can be decreased by orders magnitude upon application magnetic field. Such an effect could basis next generation memory devices. Here we report CMR antiferromagnetic oxypnictide NdMnAsO(1-x)F(x) as result competition between insulating phase and paramagnetic semiconductor Mn(2+) oxypnictides are relatively unexplored, tailored synthesis novel compounds array materials for further investigation...

CO 2 utilisation is a rapidly growing area of interest aimed at reducing the magnitude anthropogenic greenhouse gas emissions.

In the P-1 polymorph of benzanilide or N-phenylbenzamide, C(13)H(11)NO, molecules are linked into simple C(4) chains by N-H...O hydrogen bonds. The exhibit orientational disorder, but donor and acceptor in a given bond may occur, independently, either major minor orientation, such that all four possible N-H.O combinations have very similar geometries. structure this can be related to previously reported C2/c polymorph.

A novel approach to carbon sequestering using hydroxyapatite incorporate significant amounts of CO₂ with potential product applications as fertiliser.