Solid-state reaction synthesis and chemical stability studies in Nd-doped zirconolite-rich ceramics

XRD patterns of Nd-doped samples with x = 0-0.3. Nd-doped zirconolite-rich ceramics were prepared by the solid-sate reactions. Three major phases, namely zirconolite, perovskite and pseudobrookite, were observed in all these samples. Structural transition from monoclinic (2M-CaZrTi2O7) to trigonal (3T-CaZrTi2O7) happens when the Nd2O3 doping content is 7.41 wt%-10.95 wt%. In addition, the trace of Nd2O3 was not detected in all these samples, suggesting that Nd2O3 was successfully immobilized into the lattice structure as solid solution. The peaks of zirconolite gradually shift to the lower angle with the increase of Nd2O3 content. In accordance to Scherrer equation, it is reasonable to deduce that the change of average ionic radius leads to the increment of lattice constant.289