Kinetic Control of Anion Stoichiometry in Hexagonal BaTiO3

The cubic oxyhydride perovskite BaTiO3−xHx, where the well-known ferroelectric oxide BaTiO3 is partially hydridized, exhibits a variety of functions such as being catalyst and precursor for synthesis mixed-anion compounds by utilizing labile nature hydride anions. In this study, we present hexagonal version, BaTi(O3−xHx) (x < 0.6) with 6H-type structure, synthesized topochemical reaction using reduction, unlike reported oxyhydrides obtained under high pressure. conversion (150 nm) to phase heat treatment at low temperature (950~1025 °C) Mg getter allows introduction large oxygen defects (BaTiO3−x; x − 0.28) while preventing crystal growth BaTiO3, which has been accessible temperatures ~1500 °C, contributing increase hydrogen content. Hydride anions in 6H-BaTiO3−xHx preferentially occupy face-sharing sites, do other oxyhydrides.