Diffusion of sodium ions driven by charge compensation as the rate-limiting step of internal redox reactions

► Charge-compensating ions are of great importance in the dynamics of silicate melts. ► Diffusion of charge-compensating cations “rate-limits” redox reactions. ► New redox mechanism is being describe here. ► Association of network-modifier cation with trivalent network-forming cations ► Challenging in-situ high-temperature XANES experiments at the Fe K-edge.