# US 7,410,625 B2 · Process of making metal containing iron oxide and iron sulfide based nanoparticle materials > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,410,625 B2 - Document ID: US7410625B2 - Status: Granted - Kind: B2 - Application number: 11/511,715 - Filed: 2006-08-29 - Published: 2007-03-15 - Granted: 2008-08-12 - Earliest claimed: 2002-04-17 - Assignees: International Business Machines Corporation - Inventors: Shouheng Sun - Web page: https://patentgrep.com/patent/US7410625B2 ## CPC - C04B 35/628: Coating the powders {or the macroscopic reinforcing agents} - B22F 1/16: Metallic particles coated with a non-metal (coated with lubricating or binding agents or with organic material B22F1/10) - B22F 9/24: starting from liquid metal compounds, e.g. solutions - B82Y 25/00: Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance - B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites - C01G 49/08: Ferroso-ferric oxide [Fe3O4] - C01G 49/12: Sulfides {(C01G49/0018 takes precedence)} - C04B 35/62826: {Iron group metal oxides} - C04B 35/62828: {Non-oxide ceramics} - C09C 1/24: Oxides of iron - C09C 1/3054: {Coating} - C09C 3/063: {Coating} - H01F 1/0054: {Coated nanoparticles, e.g. nanoparticles coated with organic surfactant} - B22F 2998/00: Supplementary information concerning processes or compositions relating to powder metallurgy - B22F 2999/00: Aspects linked to processes or compositions used in powder metallurgy - C01P 2002/72: by d-values or two theta-values, e.g. as X-ray diagram - C01P 2004/04: obtained by TEM, STEM, STM or AFM - C01P 2004/64: Nanometer sized, i.e. from 1-100 nanometer - C01P 2006/42: Magnetic properties - C04B 2235/3272: Iron oxides or oxide forming salts thereof, e.g. hematite, magnetite - C04B 2235/3274: Ferrites - C04B 2235/5454: nanometer sized, i.e. below 100 nm - Y10S 977/773: Nanoparticle, i.e. structure having three dimensions of 100 nm or less - Y10S 977/811: Of specified metal oxide composition, e.g. conducting or semiconducting compositions such as ITO, ZnOx - C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE - B22F: WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER (making alloys by powder metallurgy C22C); APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES - C01G: COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts or peroxyacids C01B15/00; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium, or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds containing nitrogen, other non-metals and metal C01B21/082}; metal amides C01B21/092; nitrites C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; carbides C01B32/90; compounds containing silicon C01B33/00; compounds containing boron C01B35/00; compounds having molecular sieve properties but not having base-exchange properties C01B37/00; compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites, C01B39/00; cyanides C01C3/08; salts of cyanamide C01C3/16; thiocyanates C01C3/20) - C09C: TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES (treatment of materials specially adapted to enhance their filling properties in mortars, concrete or artificial stone C04B14/00, C04B18/00, C04B20/00); PREPARATION OF CARBON BLACK {; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS} - H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES - C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract A method and structure for making magnetite nanoparticle materials by mixing iron salt with alcohol, carboxylic acid and amine in an organic solvent and heating the mixture to 200-360° C. is described. The size of the particles can be controlled either by changing the iron salt to acid/amine ratio or by coating small nanoparticles with more iron oxide. Magnetite nanoparticles in the size ranging from 2 nm to 20 nm with a narrow size distribution are obtained with the invention. ## Claims ### Claim 1 A process of making an iron oxide coated nanoparticle material comprising: mixing nanoparticles with an iron salt, an organic alcohol, an organic acid, and an organic amine in an organic solvent to produce a mixture; heating said mixture; cooling said mixture to room temperature; precipitating a product from said mixture; and dispersing said product in a solvent to produce a nanocrystal dispersion. ### Claim 2 (depends on 1) The process in claim 1, wherein said heating comprises heating said mixture to a temperature between 200° C. and 360° C. ### Claim 3 (depends on 1) The process in claim 1, wherein said nanoparticles comprise one of a metal oxide, a metal, and a polymer. ### Claim 4 (depends on 3) The process in claim 3, wherein said metal oxide comprises an oxide of one of Fe, Co, Ni, Cu, Zn, Mn, Cr, V, Ti, Mg, Ca, Ba, and Sm2O3. ### Claim 5 (depends on 3) The process in claim 3, wherein said metal comprises one of Fe, Co, Ni, Cu, Ag, Au, Pd, and Pt. ### Claim 6 (depends on 3) The process in claim 3, wherein said polymer comprises one of silica and polyhydrocarbon. ### Claim 7 (depends on 1) The process in claim 1, wherein said iron oxide comprises one of FeOx and MFexOy. ### Claim 8 A process of making an iron sulfide nanoparticle material comprising: mixing an iron salt with an organic thiol, an organic acid, and an organic amine in an organic solvent to produce a mixture; heating said mixture; cooling said mixture to room temperature; precipitating a product from said mixture; and dispersing said product in a solvent to produce a nanocrystal dispersion. ### Claim 9 (depends on 8) The process in claim 8, wherein said heating comprises heating said mixture to a temperature between 200° C. and 360° C. ### Claim 10 (depends on 8) The process in claim 8, wherein said thiol comprises any thiols from a basic formula: RSH. ### Claim 11 A process of making an iron sulfide coated nanoparticle material comprising: mixing nanoparticles with a metal salt, an organic thiol, an organic acid, and an organic amine in an organic solvent to produce a mixture; heating said mixture; cooling said mixture to room temperature; precipitating a product from said mixture; and dispersing said product in solvent to produce a nanocrystal dispersion. ### Claim 12 (depends on 11) The process in claim 11, wherein said heating comprises heating said mixture to a temperature between 200° C. and 360° C. ### Claim 13 A process of making Fe2O3 nanocrystals comprising: oxidizing Fe3O4 nanocrystals with an oxidizing agent, at a temperature above 30° C. ### Claim 14 (depends on 13) The process in claim 13, wherein said temperature is between 200° C. and 500° C. ### Claim 15 (depends on 13) The process in claim 13, wherein said oxidizing agent comprises one of oxygen and peroxide. ### Claim 16 A process of making Fe-based nanocrystals comprising: reducing one of Fe3O4 and MFeOx nanocrystals with a reducing agent at a temperature above 30° C. ### Claim 17 (depends on 16) The process in claim 16, wherein said temperature is between 250° C. and 500° C. ### Claim 18 (depends on 16) The process in claim 16, wherein said Fe nanocrystals comprise one of a bimetallic FeM, where M=Co, and Ni, Cn, Zn, Cr, and a multi-metallic CoFeSmx, CoFeMox. ### Claim 19 (depends on 16) The process in claim 16, wherein said reducing agent comprises one of hydrogen, a metal hydride, and a unit adapted to give out electrons.