Role of non-bridging oxygen defect in the ionic conductivity and associated oxygen trap centers in lead-borate oxide glass: Effect of structural substitution of PbO for Ag2O and Li2O modifiers

The relaxation frequency peaks observed in the temperature dependent capacitance-frequency measurements indicated that the incorporation of Ag2O and Li2O in lead-borate network produces a non-bridging Oxygen hole centers (NBOHC) trap defect. This relaxation takes place due to an emission from shallow acceptor NBOHC like defect level with an activation energy ≤52 meV for the investigated compositions.