Abstract: A method for producing coated, fine metal particles each having a Ti oxide coating and a silicon oxide coating formed in this order on a metal core particle by mixing powder comprising TiC and TiN with oxide powder of a metal M meeting the relation of ?GM-O>?GTiO2, wherein ?GM-O represents the standard free energy of forming an oxide of the metal M; heat-treating the resultant mixed powder in a non-oxidizing atmosphere to reduce the oxide of the metal M with the powder comprising TiC and TiN, while coating the resultant metal M particles with Ti oxide; coating the Ti-oxide-coated surface with silicon oxide; and classifying the resultant particles such that they have a median diameter d50 of 0.4-0.7 ?m, and a variation coefficient (=standard deviation/average particle size) of 35% or less, which indicates a particle size distribution range.

Abstract: Fine composite metal particle comprising a metal core and a coating layer of carbon, and being obtained by reducing metal oxide powder with carbon powder.

Abstract: Fine composite metal particle comprising a metal core and a coating layer of carbon, and being obtained by reducing metal oxide powder with carbon powder.

Abstract: Fine composite metal particle comprising a metal core and a coating layer of carbon, and being obtained by reducing metal oxide powder with carbon powder.

Abstract: A method for producing fine, coated metal particles comprising the steps of mixing Ti-containing powder except for Ti oxide powder with oxide powder of a metal M, an M oxide having a standard free energy of formation meeting the relation of ?GM-O>?GTiO2; and heat-treating the resultant mixed powder at a temperature of 650-900° C. in a non-oxidizing atmosphere, thereby reducing the oxide of the metal M with Ti to provide the resultant fine particles of the metal M with TiO2-based titanium oxide coating.

Abstract: Fine metal particles each comprising a magnetic metal core particle and two or more coating layers, the outermost layer among the two or more coating layers containing an oxide of silicon and aluminum at an Al/Si atomic ratio of 0.01-0.2, and a method for producing fine metal particles comprising the steps of coating each primary particle comprising a magnetic metal core particle and a first coating layer with a mixture of silicon alkoxide and aluminum alkoxide, and then hydrolyzing the silicon alkoxide and the aluminum alkoxide, thereby forming a second coating layer comprising an oxide of silicon and aluminum at an Al/Si atomic ratio of 0.01-0.2.

Abstract: A method for producing coated, fine metal particles comprising the steps of mixing powder comprising TiC and TiN with powder of an oxide of a metal M meeting the relation of ?GM-O>?GTiO2, wherein ?GM-O represents the standard free energy of formation of metal M oxide, and heat-treating the resultant mixed powder in a non-oxidizing atmosphere to reduce the oxide of the metal M with the powder comprising TiC and TiN, while coating the resultant metal M particles with Ti oxide, and coated, fine metal particles each comprising a metal core particle and a Ti oxide coating and having a carbon content of 0.2-1.4% by mass and a nitrogen content of 0.01-0.2% by mass.

Abstract: A method for producing fine, coated metal particles comprising the steps of mixing Ti-containing powder except for Ti oxide powder with oxide powder of a metal M, an M oxide having a standard free energy of formation meeting the relation of ?GM-O>?GTiO2; and heat-treating the resultant mixed powder at a temperature of 650-900° C. in a non-oxidizing atmosphere, thereby reducing the oxide of the metal M with Ti to provide the resultant fine particles of the metal M with TiO2-based titanium oxide coating.

Abstract: Fine composite metal particle comprising a metal core and a coating layer of carbon, and being obtained by reducing metal oxide powder with carbon powder.

Abstract: Fine composite metal particle comprising a metal core and a coating layer of carbon, and being obtained by reducing metal oxide powder with carbon powder.

Abstract: Fine composite metal particle comprising a metal core and a coating layer of carbon, and being obtained by reducing metal oxide powder with carbon powder.

Abstract: Fine composite metal particle comprising a metal core and a coating layer of carbon, and being obtained by reducing metal oxide powder with carbon powder.

Abstract: A sintered rare earth magnet is produced by finely pulverizing a coarse rare earth magnet alloy powder to an average particle size of 1-10 &mgr;m in a non-oxidizing atmosphere; introducing the resultant fine rare earth magnet alloy powder into a non-oxidizing liquid comprising at least one oil selected from the group consisting of mineral oils, synthetic oils and vegetable oils, and at least one lubricant selected from the group consisting of esters of aliphatic acids and monovalent alcohols, esters of polybasic acids and monovalent alcohols, esters of aliphatic acids and polyvalent alcohols and their derivatives to prepare a slurry; molding the slurry; degreasing the resultant green body; sintering the degreased green body; and then heat-treating the green body.

Abstract: An R—T—B rare earth sintered magnet containing an R2T14B-type intermetallic compound as a main phase and thus having improved squareness ratio is produced by carrying out a reduction and diffusion method comprising the steps of (a) mixing oxide powder of at least one rare earth element R, T-containing powder, wherein T is Fe or Fe and Co, B-containing powder, and a reducing agent such as Ca, (b) heating the resultant mixture at 900-1350° C. in a non-oxidizing atmosphere, (c) removing reaction by-products from the resultant reaction product by washing, and (d) carrying out a heat treatment for Ca removal by heating the resultant R—T—B rare earth alloy powder at 900-1200° C. in vacuum at 1 Torr or less, followed by pulverization of the resultant alloy powder bulk, molding, sintering in vacuum, heat treatment, and surface treatment. The alloy powder bulk obtained by the heat treatment for Ca removal is preferably pulverized after removal of its surface layer.

Abstract: An R—T—B rare earth sintered magnet containing an R2T14B-type intermetallic compound as a main phase and thus having improved squareness ratio is produced by carrying out a reduction and diffusion method comprising the steps of (a) mixing oxide powder of at least one rare earth element R, T-containing powder, wherein T is Fe or Fe and Co, B-containing powder, and a reducing agent such as Ca, (b) heating the resultant mixture at 900-1350° C. in a non-oxidizing atmosphere, (c) removing reaction by-products from the resultant reaction product by washing, and (d) carrying out a heat treatment for Ca removal by heating the resultant R—T—B rare earth alloy powder at 900-1200° C. in vacuum at 1 Torr or less, followed by pulverization of the resultant alloy powder bulk, molding, sintering in vacuum, heat treatment, and surface treatment. The alloy powder bulk obtained by the heat treatment for Ca removal is preferably pulverized after removal of its surface layer.

Abstract: A sintered rare earth magnet is produced by finely pulverizing a coarse rare earth magnet alloy powder to an average particle size of 1-10 &mgr;m in a non-oxidizing atmosphere; introducing the resultant fine rare earth magnet alloy powder into a non-oxidizing liquid comprising at least one oil selected from the group consisting of mineral oils, synthetic oils and vegetable oils, and at least one lubricant selected from the group consisting of esters of aliphatic acids and monovalent alcohols, esters of polybasic acids and monovalent alcohols, esters of aliphatic acids and polyvalent alcohols and their derivatives to prepare a slurry; molding the slurry; degreasing the resultant green body; sintering the degreased green body; and then heat-treating the green body.

Abstract: A thin arc segment magnet made of a rare earth sintered magnet substantially comprising 28-33 weight % of R and 0.8-1.5 weight % of B, the balance being substantially Fe, wherein R is at least one rare earth element including Y, and T is Fe or Fe and Co, which has an oxygen content of 0.3 weight % or less, a density of 7.56 g/cm3 or more, a coercivity iHc of 1.1 MA/m (14 kOe) or more at room temperature, and an orientation Br/4&pgr;Imax of 96% or more in an anisotropy-providing direction at room temperature can be produced by using a slurry mixture formed by introducing fine alloy powder of the above composition into a mixture liquid comprising 99.7-99.99 parts by weight of a mineral oil, a synthetic oil or a vegetable oil and 0.01-0.3 parts by weight of a nonionic surfactant and/or an anionic surfactant.

Abstract: A thin arc segment magnet made of a an R-T-B based, rare earth sintered magnet substantially comprising 28-33 weight % of R and 0.8-1.5 weight % of B, the balance being substantially Fe T, wherein R is at least one rare earth element including Y, and T is Fe or Fe and Co, which has an oxygen content of 0.3 weight % or less, a density of 7.56 g/cm3 or more, a coercivity iHc of 1.1 MA/m (14 kOe) or more at room temperature, and an orientation Br/4?Imax of 96% or more in an anisotropy-providing direction at room temperature can be produced by using a slurry mixture formed by introducing fine alloy powder of the above composition into a mixture liquid comprising 99.7-99.99 parts by weight of a mineral oil, a synthetic oil or a vegetable oil and 0.01-0.3 parts by weight of a nonionic surfactant and/or an anionic surfactant.