Composition variations and UV irradiation effect on charge transfer in PbMoO4 single crystals

Анотація

The effect of nonstoichiometry of the composition, PbO polymorphism, and preliminary irradiation with ultraviolet light on electrical conductivity of alternating current (AC) was studied in PbMoO₄ crystals. The crystals were grown by Czochralski method in a direction deviated by 30° from a-axis in (001) plain. The charge was prepared from MoO₃ and PbO, lead oxide was used of α- or β- structural modifications. The reagents were taken both in a stoichiometric ratio and with an excess of 0.5 mol % of MoO₃. It was shown that the magnitude of the dark and irradiation-induced AC conductivity was affected both by the type of polymorphic form of PbO and by the excess amount of MoO₃. The influence of the PbMoO₄ crystal structural disorder on charge transfer processes are discussed within the framework of the model of hopping conduction in disordered media.