CERIUM OXIDE AND METHOD FOR PRODUCING THE SAME

摘要

Disclosed are a cerium oxide and a method for producing the cerium oxide. Specifically disclosed is a cerium oxide which enables to obtain high smoothness comparable to that realized by a colloidal silica when used as a polishing material, while having high polishing rate. The cerium oxide enables to have a polished surface with good cleanability. More specifically disclosed is a cerium oxide having an average particle diameter of not more than 0.5 µm and a crystallite diameter of 8-80 nm. When the cerium oxide is formed into a cerium oxide slurry containing the cerium oxide in a 3% by mass saline solution at a concentration of 2% bymass,the slurry has a certain sedimentation volume. Specifically, the sedimentation volume is within the range of 2.5-15.0 mL/g when the cerium oxide slurry is left at rest for 24 hours after stirring.