Structure of semiconducting versus fast-ion conducting glasses in the Ag-Ge-Se system.

The transition from a semiconductor to a fast-ion conductor with increasing silver content along the Ag (GeSe) tie line (0≤≤25) was investigated on multiple length scales by employing a combination of electric force microscopy, X-ray diffraction, and neutron diffraction. The microscopy results show separation into silver-rich and silver-poor phases, where the Ag-rich phase percolates at the onset of fast-ion conductivity. The method of neutron diffraction with Ag isotope substitution was applied to the =5 and =25 compositions, and the results indicate an evolution in structure of the Ag-rich phase with change of composition.

High-pressure transformation of SiO₂ glass from a tetrahedral to an octahedral network: a joint approach using neutron diffraction and molecular dynamics.

A combination of in situ high-pressure neutron diffraction at pressures up to 17.5(5) GPa and molecular dynamics simulations employing a many-body interatomic potential model is used to investigate the structure of cold-compressed silica glass. The simulations give a good account of the neutron diffraction results and of existing x-ray diffraction results at pressures up to ~60  GPa.

Mechanisms of network collapse in GeO2 glass: high-pressure neutron diffraction with isotope substitution as arbitrator of competing models.

The structure of the network forming glass GeO(2) is investigated by making the first application of the method of in situ neutron diffraction with isotope substitution at pressures increasing from ambient to 8 GPa. Of the various models, the experimental results are in quantitative agreement only with molecular dynamics simulations made using interaction potentials that include dipole-polarization effects. When the reduced density ρ/ρ(0) > or approximately equal to 1.

Density-driven structural transformations in network forming glasses: a high-pressure neutron diffraction study of GeO2 glass up to 17.5 GPa.

The structure of GeO(2) glass was investigated at pressures up to 17.5(5) GPa using in situ time-of-flight neutron diffraction with a Paris-Edinburgh press employing sintered diamond anvils. A new methodology and data correction procedure were developed, enabling a reliable measurement of structure factors that are largely free from diamond Bragg peaks.