New free-solute ferrocene/ferricinium electrochemistry, in liquid electrolyte on TI-containing oxocuprate superconducting electrodes studied at several temperatures above and below T, shows no discontinuities or abnormalities at the transition, in contrast with solid-electrolyte behaviour but possibly in accord with theoretical predictions regarding vibronic interactions or reorganisation barriers.

Enhanced Oxide Ion Conductivity in Stabilized δ-Bi2O3. -Bi12.5Ln1.5O24.5 (Ln: La, Nd, Eu, Er, Y) materials are synthesized by reaction of stoichiometric amounts of Bi2O3, Ln2O3, and NH4ReO4 (Bi:Ln:Re = 12.5:1.5:1; air, 800°C, 36 h). The samples are characterized by powder XRD and conductivity measurements. Ln-and Re-doped δ-Bi2O3 materials exhibit low-temperature (<400°C) oxide ion conductivities that are significantly higher than previously reported for δ-Bi2O3 phases and are comparable to those of BIMEVOX (e.g. Bi 2 V 0.9 Cu 0.1 O 5.35 ) materials, with the La containing phase showing the highest conductivity. These materials offer excellent potential for low temperature applications in non-reducing conditions as ceramic oxygen generators e.g., for portable oxygen supplies. -(PUNN, R.; FETEIRA, A. M.; SINCLAIR, D. C.; GREAVES*, C.; J.

This is a repository copy of Multiple local symmetries result in a common average polar axis in high-strain BiFeO3-based ceramics.

A new computational analysis of tilt behaviour in perovskites is presented. This includes the development of a computational program – PALAMEDES – to extract tilt angles and the tilt phase from molecular dynamics simulations. The results are used to generate simulated selected-area electron and neutron diffraction patterns which are compared with experimental patterns for CaTiO3. The simulations not only reproduced all symmetrically allowed superlattice reflections associated with tilt but also showed local correlations that give rise to symmetrically forbidden reflections and the kinematic origin of diffuse scattering.

The title solid solutions are prepared from stoichiometric mixtures of BaCO3, TiO2, and Co3O4 (Pt crucible, 1648 K for 2 d (y = 0.1), 1473 K for 3 d (y = 0.2), 1373 K for 3 d (y = 0.3), 1398 K for 6 d (y = 0.4)).

0.8 O 2.80 . -The new title compound is prepared from a ground stoichiometric mixture of BaCO3, MnCO3, and Co3O4 (1000°C, 2 d). The samples are characterized by XRD, neutron diffraction, SAED, HREM, EELS, magnetic measurements, and impedance spectroscopy. BaMn0.2Co0.8O2.80 crystallizes in the hexagonal space group P3m1. The structure consists of [MnCo2O12] blocks of three face-sharing octahedra linked by corners to two unconnected [CoO 4 ] tetrahedra. BaMn0.2Co0.8O2.80 exhibits internal barrier layer capacitor behavior with a high and temperature-stable permittivity close to 10000. -(MIRANDA, L.; FETEIRA, A.; SINCLAIR, D. C.; GARCIA HERNANDEZ, M.; BOULAHYA, K.; HERNANDO, M.; VARELA, A.; GONZALEZ-CALBET, J. M.; PARRAS*, M.; Chem. Mater. 20

. -The crystal and magnetic structures and electrical properties of BaMn0.85Fe0.15O2.87 and BaMn0.6Fe0.4O2.72, two new compounds in the title system, are characterized by X-ray, electron, and neutron diffraction, HREM, Moessbauer spectroscopy, impedance spectroscopy, and magnetization measurements. The compounds crystallize in the 6H' hexagonal polytype in the space group P6m2. The structure contains tetramers and dimers of face-sharing octahedra that are linked by corners. The magnetic structure is formed by ferromagnetic sheets stacked antiferromagnetically. Both compounds behave as leaky insulators at room temperature. -(MIRANDA, L.; SINCLAIR, D. C.; HERNANDO, M.; VARELA, A.; WATTIAUX, A.; BOULAHYA, K.; GONZALEZ-CALBET, J. M.; PARRAS*, M.; Chem. Mater.

The effect of calcining in either air (VSTO-A) or 5% H2/N2 (VSTO-H) on the thermoelectric performance of La and Sm co-doped A-site-deficient Sr1-3x/2Lax/2Smx/2TiO3-δ ceramics is reported. All calcined powders were sintered 6 h in 5% H2/N2 at 1773 K to ≥96% relative density. All peaks in X-ray diffraction patterns indexed as a cubic perovskite phase. Scanning electron microscopy revealed grain sizes ~14 and ~10 μm for VSTO-A and VSTO-H ceramics, respectively. x = 0.30 showed the lowest k (2.99 W/m.K at 973 K) for VSTO-A, whereas x = 0.20 had the lowest (2.67 W/m. K at 973 K) for the VSTO-H ceramics. x = 0.30 VSTO-A showed a thermoelectric figure of merit, ZT = 0.25 (at 973 K), whereas the maximum ZT = 0.30 (at 973 K) was achieved for x = 0.20 VSTO-H ceramics, demonstrating that thermoelectric properties are optimized when all processing is carried out in 5% H2/N2.