Tracking of structural defects induced by Eu-doping in β-Ag2MoO4: their influences on electrical properties

Abstract

In this study, several methods were employed to investigate the electrical characteristics of β-Ag₂MoO₄ systems, both Eu-doped and undoped, synthesized using the microwave-assisted hydrothermal method. The focus extended to understanding how synthesis time influences material defects, with doping fixed at 1%. A systematic shift in the silver vacancy (V_Ag) concentration was observed within the doped β-Ag₂MoO₄ system. Specifically, this study demonstrated that the incorporation of Eu³⁺ into polycrystalline β-Ag₂MoO₄ initially increases the V_Ag concentration. However, as the synthesis time progresses, the V_Ag concentration decreases, resulting in alterations in the resulting electrical properties, arising from the intricate interplay between the number of grain boundaries and carrier density. By combining information obtained from photoluminescence, positron annihilation lifetime spectroscopy, and impedance spectroscopy, a comprehensive conduction mechanism was formulated, shedding light on both doped and undoped β-Ag₂MoO₄ systems.