Method of producing nanosized oxide powders

• US 7,135,161 B2
• Filed: 09/04/2003
• Issued: 11/14/2006
• Est. Priority Date: 09/04/2003
• Status: Expired due to Fees

• Current Assignee: University of Florida Research Foundation, Incorporated (State University System of Florida)
• Original Assignee: University of Florida Research Foundation, Incorporated (State University System of Florida)
• Inventors: Abboudi, Mostafa, Holloway, Paul H.
• Primary Examiner(s): VANOY, TIMOTHY C
• Application Number:
  US10/656,717
• Publication Number:
  US 20050053538A1
• Time in Patent Office: 1,167 Days
• Field of Search: 423/263, 423/592.1, 423/593.1, 423/594.14, 423/604, 423/622, 423/633, 977/775, 977/777, 977/811
• US Class Current: 423/592.1
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C01B 13/18 by thermal decomposition of compounds, e.g. of salts or hydroxides
• CPC Class Codes: C01B 13/185 Preparing mixtures of oxides
• CPC Class Codes: C01F 17/229 Lanthanum oxides or hydroxides
• CPC Class Codes: C01F 17/241 containing two or more rare earth metals, e.g. NdPrO3 or LaNdPrO3
• CPC Class Codes: C01G 1/02 Oxides
• CPC Class Codes: C01G 15/00 Compounds of gallium, indium or thallium
• CPC Class Codes: C01G 49/00 Compounds of iron
• CPC Class Codes: C01P 2002/54 one element only
• CPC Class Codes: C01P 2002/72 by d-values or two theta-values, e.g. as X-ray diagram
• CPC Class Codes: C01P 2004/03 obtained by SEM
• CPC Class Codes: C01P 2004/62 Submicrometer sized, i.e. from 0.1-1 micrometer
• CPC Class Codes: C01P 2004/64 Nanometer sized, i.e. from 1-100 nanometer
• CPC Class Codes: C01P 2006/12 Surface area
• CPC Class Codes: C09K 11/623 with zinc or cadmium
• CPC Class Codes: C09K 11/7769 Oxides C09K11/7768 takes precedence
• CPC Class Codes: H01B 1/08 oxides
• CPC Class Codes: H01B 1/122 Ionic conductors
• CPC Class Codes: Y10S 977/775 Nanosized powder or flake, e.g. nanosized catalyst
• CPC Class Codes: Y10S 977/777 Metallic powder or flake
• CPC Class Codes: Y10S 977/811 : Of specified metal oxide composition, e.g. conducting or semiconducting compositions such as ITO, ZnOx

Abstract

A method of forming metal oxide powders includes the steps of solid state mixing of at least one metal nitrate salt, such as Fe(NO₃)₃ or a combination of metal nitrate salts such as Zn(NO₃)₃,6H₂O and Ga(NO₃)₃, xH₂O, and at least one reducing organic acid, such as tartaric or citric acid. The mixture is heated to form a metal oxide powder, such as alpha-iron oxide (α-Fe₂O₃) or a mixed metal powder such as zinc gallate phosphor (ZnGa₂O₄). A metal oxide precursor intermediate can be formed and then heated to form the metal oxide powder.

Claims

1. A method of forming metal oxide powders, comprising the steps of:

solid state mixing of at least one metal nitrate salt and at least one reducing organic acid having a potential of >

−

0.957 volts at standard conditions for an electron generating reaction with water to reduce said nitrate and heating to a temperature in a first temperature range to form a metal oxide precursor complex comprising said metal, and

heating said metal oxide precursor complex to a temperature of at least 200°

C. but no more than 1200°

C., wherein a metal oxide powder is formed.

2. The method of claim 1, wherein at least a portion of said heating said metal oxide precursor complex is performed in an oxygen containing atmosphere.

3. The method of claim 1, wherein said organic acid is a hydroxy acid.

4. The method of claim 3, wherein said hydroxy acid comprises tartaric acid or citric acid.

5. The method of claim 1, wherein an average particle size of said metal oxide powder is from 10 to 100 nm.

6. The method of claim 1, wherein said first temperate range is from 200 to 400°

C.

7. The method of claim 1, further comprising the step of grinding said metal oxide precursor complex before said heating said metal oxide precursor complex step.

8. The method of claim 1, wherein said metal oxide includes at least one phosphor.

9. The method of claim 1, wherein said metal oxide includes at least one ion conducting metal oxide.

10. A method of forming metal oxide powders, comprising the steps of:

solid state mixing two different metal nitrate salts and at least one reducing organic acid, and

heating said metal nitrate salts and said reducing organic acid, wherein a mixed metal oxide powder is formed.