Evolution of the phases and the polishing performance of ceria-based compounds synthesized by a facile calcination...

Ceria-based compounds with additions of La and F (CLF compounds) were prepared by using industrial-grade fluorinated lanthanum cerium carbonate as a precursor via a facile calcination method. The evolution of phase structures of the compounds during preparation and the relationship between the structure and the polishing performance were investigated. The compounds consist of three phases: CeO₂, LaOF, and LaF₃. The phase component could be controlled by tuning the calcination process. A higher degree of fluorination and a higher calcination temperature led to the formation of more LaOF and less LaF₃ phases. The LaOF phase performs a higher stock removal rate. The best polishing efficiency was achieved with LaOF phase ratio around 18%. Intermetallic LaF₃ is a low-hardness phase and is easily crushed during polishing, which lowers the removal rate and shortens the useful life of the polishing powder.