Investigations on ceria–hafnia system for phase analysis, and HT-XRD studies on a few cubic compositions

The phase relations in the system CeO2–HfO2 have been studied under slow cooled conditions. About 10 mol% of HfO2 was found to be soluble in the CeO2 lattice under these conditions. All the other compositions were found to be biphasic mixtures of F-type cubic and monoclinic phases. The lattice thermal expansion behavior was also investigated for a few single phasic as well as biphasic compositions, by means of high temperature XRD. It was found that the compositions with a higher amount of HfO2 in CeO2 lattice showed higher thermal expansion behavior.