Identification of hydrogen positions in doped BaCeO3 and SrCeO3 by neutron diffraction

Low temperature ionic conducting materials are important electrolytes for electrochemical devices such as electrolysers, fuel cells, electrochemical synthesis etc.
Fortunately, during our research at University of Warwick, we have found that the perovskite oxides SrZr0.8Y0.2O3-, CaZr0.8Y0.2O3- and SrZr0.92Y0.08O3- exhibit mixed OH−/H+ ionic conduction at a temperature below 100 °C, which is a new property of these perovskite oxides. In order to figure out the ionic conduction mechanism, it is desired to identify hydrogen and the environment of hydrogen in the hydrated oxide samples. According to previous research, the position of hydrogen in perovskite oxides BaZr0.5In0.5O3- and BaSn0.6Sc0.4O3- can be identified through the analyses of difference Fourier maps derived from the neutron diffraction patterns of the deuterated perovskite oxides. This is demonstrated by the recent success of our HRPD Xpress measurements of Ba and Sr zirconates.
During our research, it is also found that mixed OH−/H+ ionic conduction is also found in doped BaCeO3 and SrCeO3. We need to figure out the conduction mechanism of doped cerates to see if they share the same ionic conduction mechanism to the zirconates. A key requirement for proposing conduction mechanisms is to identify the position of hydrogen in hydrated perovskite oxides. Hydrogen positions also inform the position of OH- ions in the structure therefore we request neutron diffraction beamtime.