Thermal stability of nano Ce_1−xTi_xO₂material system for X < 0.2

Ceria (CeO₂) is a technologically promising compound due to a remarkable set of properties. However, the use of ceria also has drawbacks, the most pronounced of which is the material's poor thermal stability. This property limits the use of ceria-based materials at elevated temperatures, in many technological applications. To overcome this, the addition of TiO₂ is proposed. Such addition essentially creates a new material system, namely Ce_1−xTi_xO₂. In this work, an array of techniques were employed to determine the thermal stability of this new compound range (X < 0.2). Results show that when nano-sized, TiO₂is fully soluble in CeO₂ in this range. After heat treatment, however, the material coarsens and the solubility limit decreases to less than 2 at.%. as the compound undergoes significant changes. These include solute segregation and phase separation. Finally, the factors that affect compound stability are discussed.