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The crystal structure of the lithium ion conductor α-Li3.00Ga0.33SiO4 has been determined from Rietveld refinement of time-of-flight high-resolution powder neutron diffraction data. It is orthorhombic, with space group C2221, and has an oxygen arrangement that is a distortion of primitive tetragonal packing. Si, Ga and Li atoms occupy tetrahedral and octahedral sites within this oxygen framework. Li and Ga sites are fractionally occupied but certain pairs of face-sharing sites have combined occupancies of unity. The relationship between this structure and those of rutile, Li4SiO4, Li3.4Ga0.2SiO4, Li5GaSi2O8 and γ-LiAlO2 is discussed. The nature of the Li4SiO4(s.s.)–α(s.s.) phase transition is also discussed.

The measurement of the contact angles of E-glass sessile drops has been used to assess the wetting characteristics of platinum, iridium, palladium, rhodium and alloys of these materials. At each temperature studied platinum was wet more than palladium and iridium and markedly more than rhodium. The wetting behaviour has been associated with the stability of the metal oxide and a model has been proposed to explain qualitatively the relative degrees of wetting. The movement of molten glass drops situated at the junction between dissimilar metals is consistent with the proposed model.

Microscopic observation of the wetting of glass sessile drops on platinum has revealed the presence of glassy droplets in the vicinity of the wetting edge. A study of the droplets has Clarified the deposition process and the influence of the platinum grain structure on their nucleation and growth, and has allowed comment to be made on the mode of grainboundary movement during grain growth.