Abstract: An aqueous solution of a metal salt to an alkaline aqueous solution to forma hydroxide or a hydrate of a metal, and the hydroxide or hydrate of the metal is heated at a temperature of 110 to 300° C. in the presence of water. Then, the hydroxide or hydrate of the metal is filtered and dried and then further heated at a temperature of 300 to 1200° C. in an air to form oxide particles such as the particles of cerium oxide, zirconium oxide, aluminum oxide silicon oxide, iron oxide, etc. Thereby the particles of cerium oxide, zirconium oxide, aluminum oxide silicon oxide, iron oxide, etc. having a plate-form shape and a particle size of from 10 nm to 100 nm in the plate direction of the particle are obtained. The non-magnetic particles, in particular, plate-form oxide particles of the present invention have a uniform particle size distribution, are less sintered or agglomerated, and have good crystallinity.

Abstract: An aqueous solution of a tin salt and an indium salt is added to an aqueous alkaline solution to form a hydroxide or a hydrate comprising tin and indium, the hydroxide or hydrate is heated at a temperature of 110 to 300° C. in the presence of water, filtered and dried, and then the hydroxide or hydrate is heated at a temperature of 200 to 1000° C. to form the tin-containing indium oxide particles. Thereby, tin-containing indium oxide particles which have a plate-form shape and an average particle size in the plane direction of 10 to 200 nm are obtained. The tin-containing indium oxide particles are suitable for forming an electrically conductive transparent coating film.

Abstract: An aqueous solution of a tin salt and an indium salt is added to an aqueous alkaline solution to form a hydroxide or a hydrate comprising tin and indium, the hydroxide or hydrate is heated at a temperature of 110 to 300° C. in the presence of water, filtered and dried, and then the hydroxide or hydrate is heated at a temperature of 200 to 1000° C. to form the tin-containing indium oxide particles. Thereby, tin-containing indium oxide particles which have a plate-form shape and an average particle size in the plane direction of 10 to 200 nm are obtained. The tin-containing indium oxide particles are suitable for forming an electrically conductive transparent coating film.

Abstract: Non-magnetic particles, in particular, of an oxide such as cerium oxide, zirconium oxide, aluminum oxide, silicon oxide or iron oxide which have the shape of a plate and have an average particle diameter in the direction of the plate surface in a range of 10 to 100 nm; and a method for producing the above non-magnetic particles of the oxide which comprises adding a salt of the above element to an aqueous alkaline solution to provide a hydroxide or hydrate thereof, heating the hydroxide or hydrate in the presence of water at a temperature in the range of 110 to 300° C., followed by filtration and drying, and further heating the resultant product in air at a temperature in the range of 300 to 1200° C., to thereby produce particles of the oxide. The above non-magnetic particles, in particular, of on oxide has a narrow distribution of particle diameter, is extremely reduced in sintering or coagulation, and exhibits good crystallinity.