The appropriate amount of fullerene doping in phosphate and fluorophosphate
optical glasses modifies the structures of glass matrices by bonding the n
earby -[PO4]- tetrahedra with nonbridging oxygen anions, and consequently b
uilding up observable conductivity at room temperature. Non-Arrhenius ionic
conductivity is observed, which is interpreted as a result of the temperat
ure dependence of the activation energies of the mobile cations. The variat
ion of microphotoluminescence induced by the electric field presents us wit
h an indirect way to characterize the random activation, percolation migrat
ion, and retrap of metal cations near fullerene-related amorphous islands.
(C) 2001 American Institute of Physics.