A neutron diffraction study on a typical highly defective ceria-yttria solid solution

摘要

It was seen during the phase relation studies on the CeO_2-YO_(1.5) system that the ceria is able to accommodate a large anion deficiency caused by aliovalent substitution. A neutron powder diffraction study has been carried out at room temperature for the titled solid solution, Ce_(1-x)Y_xO_(2-x/2) with x = 0.32, which is an anion-deficient variant of the ideal fluorite structure. The structure has been found to be face centered cubic. No superlattice reflections have been observed indicating that the vacancies occupy the random positions in this highly defective solid solution. The bond distances and angles are also being reported.