Examining the consequences of calcium substitution on the physical properties and conduction mechanism of Y 3 GaO 6

The influence of calcium doping on the Y 3 GaO 6 system was systematically investigated for electrochemical applications. The Y 3(1− x ) Ca 3 x GaO 6 ( x = 0, 0.02, 0.04, 0.08, 0.12) ceramics compositions were prepared via conventional solid-state reaction route and their structural, electrical and electrochemical properties were investigated. The structural phase analysis revealed the formation of the orthorhombic phase with the Cmc2 1 space group. However, at higher concentrations of calcium doping, i.e. x > 0.02, a few secondary phases of Y 2 O 3 and CaCO 3 were also observed. Impedance spectra suggest an increase in the total conductivity up to x = 0.02 of Ca doping, and a decrease in the conductivity was observed for the higher concentration of Ca substitution. The substitution of Ca with x > 0.02 not only increases the oxygen vacancies rather segregates the impurities along the grain boundaries. Consequently, the impurities have negative influence on both the grain and grain-boundary conductivities. Cyclic voltammetry and Chronoamperometry studies have also been performed to characterize the samples.