Lithium niobate is a material with many important technological applications as a result of its diverse physical properties. Using a recently derived interatomic potential, intrinsic defect energies have been calculated leading to conclusions about the defect properties of the material that are compared with experimental conclusions. The incorporation of dopant ions into the structure is also considered, and solution energies are calculated, which enable predictions to be made about which ions are most easily added and which solution energy schemes are favoured energetically.

Barium fluoride (BaF2) nanoparticles (NPs) with different sizes were produced through a hydrothermal microwave method (HTMW). We have found that microstructural strain is induced by the surface stress in the nanoparticles.

This paper reports a new interatomic potential for lithium niobate, which has been fitted to the structure and properties of the stoichiometric ferroelectric phase of the material. The potential is based on a fully ionic description of the material, with the shell model being used for the oxygen ions and a three-body potential representing the interactions of the niobium ions with the neighbouring oxygen ions. The potential set has been tested on the paraelectric phase, whose structure it reproduced to within a few per cent. The calculation of lattice properties including elastic constants and dielectric constants, as well as powder x-ray diffraction patterns of both phases, are reported.

This paper describes a computational study of the mixed metal fluorides LiCaAlF 6 and LiSrAlF 6 , which have potential technological applications when doped with a range of elements, especially those from the rare earth series. Potentials are derived to represent the structure and properties of the undoped materials, then defect properties are calculated, and finally solution energies for rare earth elements are calculated, enabling preferred dopant sites and charge compensation mechanisms to be predicted.

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