Structure of alumina glass.

The fabrication of novel oxide glass is a challenging topic in glass science. Alumina (AlO) glass cannot be fabricated by a conventional melt-quenching method, since AlO is not a glass former. We found that amorphous AlO synthesized by the electrochemical anodization of aluminum metal shows a glass transition.

Controlling oxygen coordination and valence of network forming cations.

Understanding the structure-property relationship of glass material is still challenging due to a lack of periodicity in disordered materials. Here, we report the properties and atomic structure of vanadium phosphate glasses characterized by reverse Monte Carlo modelling based on neutron/synchrotron X-ray diffraction and EXAFS data, supplemented by Raman and NMR spectroscopy. In vanadium-rich glass, the water durability, thermal stability and hardness improve as the amount of PO increases, and the network former of the glass changes from VO polyhedra to the interplay between VO polyhedra and PO tetrahedra.

The structure of molten CuCl: Reverse Monte Carlo modeling with high-energy X-ray diffraction data and molecular dynamics of a polarizable ion model.

The results of the structural properties of molten copper chloride are reported from high-energy X-ray diffraction measurements, reverse Monte Carlo modeling method, and molecular dynamics simulations using a polarizable ion model. The simulated X-ray structure factor reproduces all trends observed experimentally, in particular the shoulder at around 1 Å(-1) related to intermediate range ordering, as well as the partial copper-copper correlations from the reverse Monte Carlo modeling, which cannot be reproduced by using a simple rigid ion model. It is shown that the shoulder comes from intermediate range copper-copper correlations caused by the polarized chlorides.

Medium-range correlation of Ag ions in superionic melts of Ag2Se and AgI by reverse Monte Carlo structural modelling-connectivity and void distribution.

High-energy x-ray diffraction measurements on molten Ag(2)Se were performed. Partial structure factors and radial distribution functions were deduced by reverse Monte Carlo (RMC) structural modelling on the basis of our new x-ray and earlier published neutron diffraction data. These partial functions were compared with those of molten AgI.

Comparison of partial structures of melts of superionic AgI and CuI and non-superionic AgCl.

Neutron and high-energy x-ray diffraction analyses of molten AgI have been performed and the partial structures are discussed in detail with the aid of the structural modelling procedure of the reverse Monte Carlo (RMC) technique by comparison with those of molten CuI and AgCl. It is well known that AgI and CuI have a superionic solid phase below the melting point, in which the cations favour a tetrahedral configuration, while solid AgCl has a rock-salt structure with an octahedral environment around both Ag and Cl atoms. Even in the molten states, there is a significant difference between superionic and non-superionic melts.