The interaction of lithium with sodium and potassium silicate glasses

The interaction of lithium with sodium and potassium glass surfaces in UHV has been characterized with XPS. Earlier studies of the Li/SiO₂ system have shown the formation of a partially passivating layer upon initial Li deposition. Following breakdown of this layer, substantial reduction of the glass matrix occurs. In the present study, several compositions of sodium silicate and potassium silicate glasses were found to be more resistant than SiO₂ to lithium attack owing to the presence of non‐bridging oxygens in the matrix. The proposed corrosion mechanism involves charge transfer from Li to the modifying cations at the glass surface followed by desorption of neutral Na or K and interdiffusion of Li⁺ into the glass. For thick (metallic) Li films on sodium silicates, the formation of a dilute Li—Na intermetallic and sodium metal are identified from distinct plasmon structure in the Na(1s) line. Matrix reduction of glasses with low alkali content has been observed subsequent to the atom exchange.