Crystal and Electronic Structures and High Temperature Protonic Conduction of LaBaGa_0.95Mg_0.05O_4−δ

Abstract

In this work, we synthesized LaBaGaO₄ and LaBaGa_0.95Mg_0.05O_4−δ, and investigated their crystal and electronic structures and electrical conduction properties. As a result, it was indicated that LaBaGaO₄ had an orthorhombic structure (S.G.; P2₁2₁2₁) at 298 and 900 K. The orthorhombic structure was kept even after Mg-doping although the electronic structure seemed to be varied maybe due to a partial substitution of Mg²⁺ for Ga³⁺. From an H/D isotope effect on conductivity, it was confirmed that LaBaGa_0.95Mg_0.05O_4−δ exhibited protonic conduction at elevated temperatures under a moisturized condition.