Prospective Cohort Study

Energy production and storage have become key issues concerning our welfare in daily life. Present challenges for batteries are twofold. In the first place, the increasing demand for powering systems of portable electronic devices and zero-emission vehicles stimulates research towards high energy and high voltage systems. In the second place, low cost batteries are required in order to advance towards smart electric grids that integrate discontinuous energy flow from renewable sources, optimizing the performance of clean energy sources. Na-ion batteries can be the key for the second point, because of the huge availability of sodium, its low price and the similarity of both Li and Na insertion chemistries. In spite of the lower energy density and voltage of Na-ion based technologies, they can be focused on applications where the weight and footprint requirement is less drastic, such as electrical grid storage. Much work has to be done in the field of Na-ion in order to catch up with Li-ion technology. Cathodic and anodic materials must be optimized, and new electrolytes will be the key point for Na-ion success. This review will gather the up-to-date knowledge about Na-ion battery materials, with the aim of providing a wide view of the systems that have already been explored and a starting point for the new research on this battery technology.

Na-ion batteries, recent advances and present challenges to become low cost energy storage systems

The General Utility Lattice Program (GULP) has been extended to include the ability to simulate polymers and surfaces, as well as adding many other new features, and the current status of the program is fully documented. Both the background theory is described, as well as providing a concise review of some of the previous applications in order to demonstrate the range of its use. Examples are presented of work performed using the new compatibilities of the software, including the calculation of Born effective charges, mechanical properties as a function of applied pressure, calculation of frequency-dependent dielectric data, surface reconstructions of calcite and the performance of a linear-scaling algorithm for bond-order potentials.

The general utility lattice program (GULP)

Although known since the late 19th century, organic–inorganic perovskites have recently received extraordinary research community attention because of their unique physical properties, which make them promising candidates for application in photovoltaic (PV) and related optoelectronic devices. This review will explore beyond the current focus on three-dimensional (3-D) lead(II) halide perovskites, to highlight the great chemical flexibility and outstanding potential of the broader class of 3-D and lower dimensional organic-based perovskite family for electronic, optical, and energy-based applications as well as fundamental research. The concept of a multifunctional organic–inorganic hybrid, in which the organic and inorganic structural components provide intentional, unique, and hopefully synergistic features to the compound, represents an important contemporary target.

Organic–Inorganic Perovskites: Structural Versatility for Functional Materials Design

Synthesis, properties, and applications of magnetic iron oxide nanoparticles

In order to accommodate anisotropic crystallite-size broadening effects in the Rietveld refinement of constant-wavelength powder neutron diffraction data, a modified function for the peak full width at half maximum has been evaluated for polycrystalline Ni(OD)2. The function resulted in significantly better agreement between observed and calculated profiles (the weighted residual Rw.p decreased from 14.1 to 8.5%), and structural standard deviations were reduced by an average of 43%.

Rietveld analysis of powder neutron diffraction data displaying anisotropic crystallite size broadening

The effects of partial substitution of Ba for Sr on the superconducting transition in the sulphate containing materials [Y0.74Ca0.16Sr0.1]Sr2Cu2.78(SO4)0.22O6.12 and [Y0.84Sr0.16]Sr2Cu2,78(SO4)0.22O6.12 have been investigated. As the Ba content was increased, the superconducting transitions became sharper and Tc onset increased to reach a maximum of 78 K. The cell symmetry was also observed to change from orthorhombic to tetragonal, which is thought to be associated with randomization of the orientations of the sulphate groups in the structure.

Superconductivity in the system (Y, Ca, Sr) (Ba, Sr)2 (Cu3−z(SO4)zOx

Structural characterisation of Bi2NbO5F was performed using X-ray and neutron powder diffraction and electron diffraction. Structural refinements show that the material adopts a distorted structure with significant rotation of the octahedra around two axes. The physical properties of the material have been investigated and show no evidence of polar symmetry. The structure is therefore best described by space group Pbca (a = 5.428(1) A, b = 5.426(1) A, c = 16.656(1) A). Bond valence sum calculations suggest that ordering of the anions in the structure is favourable with the fluorine atoms preferring the apices of the NbX6 (X = O/F) octahedra.

Colin Greaves

Papers

Rietveld analysis of powder neutron diffraction data displaying anisotropic crystallite size broadening

Superconductivity in the system (Y, Ca, Sr) (Ba, Sr)2 (Cu3−z(SO4)zOx

Crystal structure and electrical characterisation of Bi2NbO5F: an Aurivillius oxide fluoride

Synthesis and structural characterisation of a new perovskite phase, Ba4CaCu3O8.61

Structural and magnetic characterisation of the pyrochlores Bi2−xFex(FeSb)O7, (x=0.1, 0.2, 0.3), Nd1.8Fe0.2(FeSb)O7 and Pr2(FeSb)O7