Structural and Electrical Properties of BaPrO_3-δ Thin Film with Oxygen Vacancies

Abstract

The in-plane-oriented BaPrO_3-δ thin film with mixed valence states has been prepared on an Al₂O₃ (0001) substrate by RF magnetron sputtering. The lattice constant decreases with increasing film thickness. The thin film has the mixed valence states of Pr⁴⁺ and Pr³⁺. The ～168 nm thickness film with small lattice constant exhibits high electrical conductivity and low activation energy of 0.58 eV at dry atmosphere. The wet-annealed thin film shows high proton conduction, which is required as electrolyte of solid oxide fuel cell, at 300 ～ 600 °C.