Proton state in hydrated fluoro-substituted brownmillerites Ba2In2O5–0.5yFy∙nН2О

Abstract

Solid solutions Ba₂In₂O_5–0.5yF_y with the structure of brownmillerite are studied by IR and ¹Н MAS NMR spectroscopy. During the fluorine doping, the nearest oxygen environment of indium atoms is distorted and a part of In–O bonds is shortened. It is shown that partial fluoride ion substitution for oxygen atoms results in an increase in the proton mobility in hydrated Ba₂In₂O_5–0.5yF_y∙nН₂О phases.