Tuning of MgO nanoparticles on Ag dopant additions for charge storage applications

Abstract

Ag-doped magnesium oxide (MgO) nanoparticles (NPs) were produced through chemical precipitation method. The structural and morphological analysis of MgO particles were characterized by using XRD and TEM techniques. XRD results confirm that the crystallite size decreases after Ag doping and little amount of Ag is incorporated into MgO crystal. The dielectric properties measurement of Ag-doped MgO samples suggest that Ag doping causes its enhancement. The two possible mechanisms for the improvement of dielectric constant of Ag-doped MgO was concluded. Firstly, Ag doping would inhibit the grain growth of MgO nanoparticles, resulting in smaller size of MgO particles. Secondly, when Ag+ is doped into MgO matrix, more oxygen vacancies will be generated to keep an overall neutral charge. The ac conductivity of MgO NPs further shows improvement after doping due to relatively low electron-transfer resistance, which can accelerate the electron transfer within MgO lattice. Therefore, Ag doping can significantly promote dielectric and electrical properties of MgO NPs.