Preparation of Ce1-xSmxO2 Abrasives Using the Hydrothermal Method and Their Chemical Mechanical Polishing Performance...

Chemical mechanical polishing (CMP) is essential for manufacturing high-precision optical components. However, conventional cerium dioxide (CeO2) abrasives are often limited by their large particle size and insufficient chemical reactivity, hindering the simultaneous achievement of a high material removal rate (MRR) and a low surface roughness (Ra). To address this challenge, a series of Ce1-xSmxO2 (x = 0, 0.1, 0.15, 0.2, 0.25, or 0.3) nanoabrasives were synthesized via a one-step hydrothermal method, aiming to enhance the polishing performance by modulating the electronic structure of CeO2. The results demonstrate that appropriate Sm substitution increases the surface concentrations of Ce3+ and oxygen vacancies to 35.64% and 29.33%, respectively. Notably, Ce0.8Sm0.2O2 exhibits optimal comprehensive performance in the polishing of K9 glass. The MRR reaches 579.86 nm/min, representing a 168.90% increase over that of commercially available CeO2, while the Ra is reduced to 0.44 nm, a decrease of 45.68%. A comparative analysis with other rare-earth elements such as La, Pr, Y, and Lu in CeO2 systems demonstrates the unique advantage of Sm substitution in enhancing the polishing activity of CeO2. The significant improvement in performance is attributed to an enhanced "chemical tooth" mechanism driven by a high concentration of active sites (Ce3+/oxygen vacancies). Under mechanical pressure, the active sites form Ce-O-Si bonds with the SiO2 surface, electron transfer weakens the Si-O bonds, and mechanical shearing then enables the efficient and uniform removal of the material. This study provides a clear experimental basis for the design of high-performance polishing materials for advanced manufacturing.