Preparation and chemical mechanical polishing performance of CeO2/CeF3 composite powders

This work reported a simple route for preparing CeO2/CeF3 composite powders. Cerium nitrate hexahydrate, oxalic acid dihydrate and ammonium fluoride were milled and subsequently calcined to obtain the composite powders. X-ray diffractometer, field emission scanning electron microscope, transmission electron microscopy, zeta potential tester, and polishing test were utilised to characterise those products and study the effect of doped fluorine amount on their physicochemical characteristics and chemical mechanical polishing properties. The results show that incorporation of 7 wt% fluorine into the starting materials can change the particle morphology from large sheet for pure CeO2 into uniform spherical particles with size of 30-50 nm. The composite powder with 7 wt% fluorine exhibits great suspension stability and relatively high material removal rate. Meanwhile, this slurry facilitates obtaining smoother surface after polishing, which may be related to the changes of particle morphology and decrease in overall hardness of abrasives.