PNNL

Abstract

Rare earth elements are commonly used as analogs for studying actinide chemistry without the inherent radiological risks that actinides present. Here, cerium was used to investigate the nucleation and growth of metal oxalates. Using in- situ liquid cell TEM (LC-EM), we show the occurrence of particle attachment processes during the nucleation and growth of cerium oxalate. These non-classical growth mechanisms will have important implications for the evolution of particle growth and predictions of particle morphology. We observed the monomer-by-monomer addition and particle aggregation pathway exist depending on the precursor concentration. The results also demonstrate that the branch structure formed in the high precursor concentration at high dose rate due to the interfacial instability.