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

The synthesis of the copper oxyfluoride, Ca2CuO2F2+δ, by reaction of Ca2CuO3 with elemental F2 at low temperatures (240 °C) is reported. Preliminary structure refinement of powder neutron diffraction data suggests that Ca2CuO2F2+δ is structurally related to Nd2CuO4, rather than to the La2CuO4 structure observed for the related copper oxyfluoride, Sr2CuO2F2+δ. The proposed change in structure type is attributed to the decrease in the size of the alkaline-earth cation. Madelung energy calculations support the view that fluorine insertion causes O/F interchange to give CuO2 planes with the fluorine atoms located between the Ca bilayers. Although the structure could potentially support superconductivity, no evidence for superconductivity has so far been found in this phase down to 4 K.

Synthesis and structure of the calcium copper oxyfluoride, Ca2CuO2F2+δ

The defect structure of tin–antimony oxide has been investigated by profile refinement of powder neutron diffraction data. The structure, based on the occupation by antimony(III) of interstitial positions within the tin(IV) oxide rutile-type lattice, is described and the model used to rationalise some of the properties of the mixed oxide.

A neutron diffraction investigation of the defect rutile structure of tin–antimony oxide

Fluorine insertion reactions of the brownmillerite materials Sr2Fe2O5, Sr2CoFeO5, and Sr2Co2O5

A new layered manganese oxide, Sr2MnGaO5,
has been synthesised and Rietveld analysis of X-ray powder diffraction data
has shown it to be an oxygen deficient perovskite with the brownmillerite
structure: a = 5.5033(6) A, b = 16.234(2) A, c = 5.3717(6) A. Incomplete
order of the oxygen vacancies is best described using the space group Icmm.
The oxygen content can readily be varied to form Sr2MnGaO5 + δ
(0 ≤ δ ≤ 0.5) to provide Mn oxidation states
between Mn(III) and Mn(IV).

Synthesis and structure of Sr2MnGaO5,a new layered manganese oxide

The low temperature fluorination of low dimensional mixed metal oxides can be achieved in a variety of ways to provide new structures and modified electronic characteristics The potential of these methods for the synthesis of new materials is considered, with particular reference to the fields of copper oxide superconductors and layered manganese oxide colossal magnetoresistance (CMR) phases; in both areas, careful structural and electronic control is necessary for optimised properties The fluorination mechanisms are quite complex, and this paper describes the synthesis of three new oxide fluorides: La
 19
Sr
 11
Cu
 2
O
 5
F
 2
, PbSr
 2
YCu
 3
O
 6
F
 4
 and La
 12
Sr
 18
Mn
 2
O
 7
F
 2
, via processes which involve anion insertion, anion substitution and cation extraction The use of a related strategy to incorporate more complex anions into oxides is also discussed, and the assimilation of SO
 4

 2–
 ions into Bi
 2
O
 3
 to give phases of composition Bi
 2
O
 3–x
(SO
 4
)
 x
 is described

Colin Greaves

Papers

Synthesis and structure of the calcium copper oxyfluoride, Ca2CuO2F2+δ

A neutron diffraction investigation of the defect rutile structure of tin–antimony oxide

Fluorine insertion reactions of the brownmillerite materials Sr2Fe2O5, Sr2CoFeO5, and Sr2Co2O5

Synthesis and structure of Sr2MnGaO5,a new layered manganese oxide

Synthetic strategies for new inorganic oxide fluorides and oxide sulfates