Isothermal nanocrystallization of vanadate–phosphate glasses

Glasses of the nominal composition of 90V2O5 · 10P2O5 were prepared by a standard melt-quenching technique. Their thermal and electrical properties during isothermal annealing have been studied by DSC and impedance spectroscopy. Time dependences of crystallization observed in isothermal DSC experiments at a set of temperatures were satisfactorily fitted with the Avrami formula. The progress in crystallization during the annealing resulted in a monotonic increase in the electronic conductivity. The conductivity changes were adequately represented by a proposed theoretical model of conductivity changes caused by isothermal nanocrystallization.