Emergence of Conduction Channels in Lithium Silicate

The existence of conduction channels in lithium silicate (Li_2O)(SiO_2) is investigated. Regions of the system where many different ions pass by form channels and are thus spatially correlated. For a closer analysis the properties of the individual ionic sites are elucidated. The mobility of ions in single sites is found to depend strongly on the number of bridging oxygens in the coordination shell. The channels are not reflected in the network structure as obtained from the distribution of the bridging oxygens. Spatial correlations similar to those found in the silicate also emerge from studying the dynamics of particles in a simple random lattice model. This supports the suggestion that the observed spatial correlations can be viewed in analogy to the emergence of percolation paths.