It was pointed out that protons in some alkaline earth metal phosphate glasses were much more mobile than monovalent ions such as Na+ and Ag+ under a direct-current electric field. It was concluded that the mobilities of protons depended markedly upon the glass structure and the composition. Thus, H-bonded protons were much more mobile than monovalent cations in some glasses. For examples, in Ba and Ca phosphate glasses, the strength of O-H bonding was weakened when the proton was strongly H-bonded to neighboring non-bridging O ions. Therefore, the protons were easily released for conduction. It was expected that phosphate glasses could be developed in which a large number of H-bonded protons and/or water molecules were created. Such glasses would be stable in ambient atmospheres and would exhibit conductivities of about 0.001S/cm at room temperature.

Y.Abe, H.Hosono, O.Akita, L.L.Hench: Journal of the Electrochemical Society, 1994, 141[6], L64-5