Structural investigation of sintered zirconia ceramics for nuclear applications - effects of Ce/Nd dopants and synthesis methods

• Final structure depends on both synthesis route and type of dopant (Ce/Nd). • Dry synthesis enables better Ce/Nd incorporation into ZrO2 than mechanical alloying. • Dual sublattice ordering in sol-gel ZrO2: cations at calcination, anions after SPS. • Dopants incorporation increases lattice parameters and stabilizes tetragonal/cubic phases. The novelty of this work lies in the comprehensive investigation of neodymium and cerium doped zirconia ceramics structure through X-ray diffraction, Raman spectroscopy and fourier-transform infrared spectroscopy. This combination made it possible to identify a previously unknown difference in ordering cationic and anionic sublattices in sol-gel samples for these materials. Furthermore, the sol-gel method was compared with mechanical alloying, and Spark Plasma Sintering followed each. For these synthesis routes, Nd(III) and/or Ce(IV) ions were employed as substitutes for radioactive minor actinides to simulate structural changes in an inert fuel matrix. The final structure of the ceramics proved to be highly dependent on both the type of dopant and the synthesis method, with the successful incorporation of Ce and Nd ions resulting in significant changes in crystallographic lattice parameters. These findings enhance the understanding of the role of Ce and Nd as substitutes for minor actinides and expand the potential for applying zirconia-based ceramics in nuclear technologies.