Phase formation, microstructure, and electric conductivity of ion-conductive ceramics based on lanthanum gallate

Abstract

Ceramic samples in the (La_0.8Sr_0.2){[Ga_0.8–x(Si_0.5Mg_0.5)_x]Mg_0.2}O_3–d system (LSGSM) (x = 0, 0.1, 0.2, 0.4, 0.6, 0.8) were obtained by solid-phase synthesis, and their phase formation, structure, microstructure, and electric conductivity were studied. The substitution of gallium cations by silicon and magnesium cations was found to affect the phase formation, structure, microstructure, and electric conductivity of the ceramics. The replacement of up to 10 at % gallium cations by silicon and magnesium cations led to the formation of single-phase solid solutions in the LSGSM system. The silicon-containing samples are characterized by high density, optimum microstructure, close packing of grains, and high electric conductivity at high temperatures.