The object of the present invention is to provide silicon doped metal oxide particles for UV absorption, which average molar absorption coefficient in the wavelength range of 200 nm to 380 nm, is enhanced. Provided is silicon doped metal oxide particles in which the metal oxide particles are doped with silicon, wherein an average molar absorption coefficient in the wavelength range of 200 nm to 380 nm, of a dispersion in which the silicon doped metal oxide particles are dispersed in a dispersion medium, is improved as compared with similar metal oxide particles not doped with silicon.

The present disclosure relates to a method for producing metal oxide nanoparticles includes a first step of preparing a reaction solution containing a metal complex, an alcohol, and water; a second step of heating the reaction solution for phase-separation under a hermetically sealed atmosphere where the volumetric expansion ratio of the reaction solution reaches 5 to 15%; a third step of holding the reaction solution heated in the second step for 30 minutes or more for dehydrating the metal complex to precipitate the metal oxide nanoparticles; and a fourth step of collecting the metal oxide nanoparticles after the metal oxide nanoparticles are cooled.

The present disclosure relates to a method for producing metal oxide nanoparticles includes a first step of preparing a reaction solution containing a metal complex, an alcohol, and water; a second step of heating the reaction solution for phase-separation under a hermetically sealed atmosphere where the volumetric expansion ratio of the reaction solution reaches 5 to 15%; a third step of holding the reaction solution heated in the second step for 30 minutes or more for dehydrating the metal complex to precipitate the metal oxide nanoparticles; and a fourth step of collecting the metal oxide nanoparticles after the metal oxide nanoparticles are cooled.

An object of the present invention is to provide a nanobubble-containing inorganic oxide fine particle dispersion having excellent concentration stability in a process used as an abrasive. The object is achieved by the nanobubble-containing inorganic oxide fine particle dispersion including: inorganic oxide fine particles having an average particle size of 1 to 500 nm and containing fine particles containing Ce; and nanobubbles having an average cell size of 50 to 500 nm and being at least one non-oxidizing gas selected from a group consisting of N.sub.2 and H.sub.2.

Described herein are compositions and methods relating to molecular cerium-oxide nanoclusters. Described herein are methods of producing cerium-oxide nanoclusters. Described herein are cerium-oxide nanoclusters. Further described herein are cerium-oxide nanoclusters produced by methods as described herein. Methods as described herein can comprise providing a first cerium source, an organic acid, and a solvent; and mixing the cerium source and the organic acid in the presence of a solvent to create a reaction mixture at a temperature and a pressure for a period of time to create a composition of molecular cerium-oxide nanoclusters containing a plurality of molecular cerium-oxide nanoclusters.

Described herein are compositions and methods relating to molecular cerium-oxide nanoclusters. Described herein are methods of producing cerium-oxide nanoclusters. Described herein are cerium-oxide nanoclusters. Further described herein are cerium-oxide nanoclusters produced by methods as described herein. Methods as described herein can comprise providing a first cerium source, an organic acid, and a solvent; and mixing the cerium source and the organic acid in the presence of a solvent to create a reaction mixture at a temperature and a pressure for a period of time to create a composition of molecular cerium-oxide nanoclusters containing a plurality of molecular cerium-oxide nanoclusters.

A slurry containing abrasive grains and a liquid medium, in which the abrasive grains include first particles and second particles in contact with the first particles, the first particles contain cerium oxide, the second particles contain a cerium compound, and in a case where a content of the abrasive grains is 2.0% by mass, a BET specific surface area of a solid phase obtained when the slurry is subjected to centrifugal separation for 30 minutes at a centrifugal acceleration of 1.1×10.sup.4 G is 24 m.sup.2/g or more.

A slurry containing abrasive grains and a liquid medium, in which the abrasive grains include first particles and second particles in contact with the first particles, the first particles contain cerium oxide, the second particles contain a cerium compound, and in a case where a content of the abrasive grains is 2.0% by mass, a BET specific surface area of a solid phase obtained when the slurry is subjected to centrifugal separation for 30 minutes at a centrifugal acceleration of 1.1×10.sup.4 G is 24 m.sup.2/g or more.

A cerium oxide nanoparticle is produced by mixing a solution of an aromatic heterocyclic compound having no substituent or at least one substituent selected from the group consisting of a methyl group, an ethyl group, an amino group, an aminomethyl group, a monomethylamino group, a dimethylamino group, and a cyano group and containing 2 to 8 carbon atoms and 1 to 4 nitrogen atoms in a ring structure of the aromatic heterocyclic compound, with a solution containing a cerium (III) ion or with a cerium (III) salt, followed by addition of an oxidant.

A cerium oxide nanoparticle is produced by mixing a solution of an aromatic heterocyclic compound having no substituent or at least one substituent selected from the group consisting of a methyl group, an ethyl group, an amino group, an aminomethyl group, a monomethylamino group, a dimethylamino group, and a cyano group and containing 2 to 8 carbon atoms and 1 to 4 nitrogen atoms in a ring structure of the aromatic heterocyclic compound, with a solution containing a cerium (III) ion or with a cerium (III) salt, followed by addition of an oxidant.