Alkaline multicomponent phosphate glass for modification of properties by ion exchange

Abstract On the basis of concepts presented on the structure of glass considered favorable for complete ion exchange of monovalent cations in the `glass–salt melt' system, a composition of alkaline multicomponent phosphate glass has been proposed, which is effective in speeding the process of interdiffusion of alkaline cations. The glass of composition, Me2O–RxOy–P2O5 where Me2O=Na2O + K2O and RxOy=B2O3 + ZrO2 + Nb2O5 + Al2O3 + SiO2 + Nd2O3 (formula unit) has been chosen as the initial one for ion exchange. During the ion exchange, gradient diffusion layers up to 1.7 mm thick have been obtained in 8 h from a molten mixture of Li2SO4 and Li2MoO4, at temperatures above the glass transition temperature over the flat surface of a sample; the increase of the refractive index in the layer was equal to 0.027±0.002.