Exploring the local structure of complex doped ceria systems by PDF analyses

With the proposed experiment we aim to perform pair distribution function (PDF) analyses on 16 samples belonging to the Ce1-x(Nd0.74Tm0.26)xO2-x/2 and the Ce1-x(Nd0.63Dy0.37)xO2-x/2 systems (x= 0.05-0.60). PDF analyses will be performed to gain information on the local structure of the present systems, trying to unravel the non-trivial relationship between their ionic conductivity and local structure. In fact, in Ce1-xRExO2-x/2 systems (RE= trivalent rare earth ion), the high ionic conductivity observed between 673 and 973 K at low dopant amount is strictly related to the structural properties, even at the local scale, and to the occurrence of defect aggregates. Consequently, an in-depth structural study is fundamental to evaluate the chemical nature and the amount of the doping ions giving rise to the most efficient electrolytes for a possible application in solid oxide cells working at the intermediate temperature range.