Emergence of Conduction Channels in Lithium Silicate

TL;DR

This paper investigates the formation of conduction channels in lithium silicate, revealing that ion mobility depends on local site structure and that channels emerge through spatial correlations akin to percolation paths, independent of the network structure.

Contribution

It demonstrates that conduction channels in lithium silicate arise from spatial correlations and local site properties, not directly from the network structure, supported by a simple lattice model.

Findings

Ion mobility depends on bridging oxygens in coordination shells.

Conduction channels are spatially correlated and resemble percolation paths.

Channels are not reflected in the network structure.

Abstract

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.