Location of deuterium atoms in BaSn0.5In0.5O2.75+α at 77–473 K by neutron powder diffraction

This paper describes the location of deuterium atoms in BaSn0.5In0.5O2.75 by neutron powder diffraction at 77 K, room temperature and 473 K. The diffraction data were collected on BaSn0.5In0.5O2.75 with and without dissolved D2O, and analyzed by the Rietveld method and the maximum entropy method. It was found that deuterium atoms were located at or very close to the 12h site of the cubic perovskite structure (space group Pm3¯m) with an O–D distance of 1.0 Å at these temperatures. This deuterium site is basically the same as that at 10 K and similar to those suggested by the previous computational studies for proton-conducting perovskite oxides.