| Title: |
Magnetic nanomaterials and synthesis method |
| Document Number: |
20050200438 |
| Publication Date: |
September 15, 2005 |
| Appl. No: |
10/505701 |
| Application Filed: |
February 06, 2003 |
| Abstract: |
A magnetic nanoparticle (22), a magnetic nanomaterial (30), assembly (30), and a method for synthsising a magnetic nanoparticle, relating to thermodynamically stable and air stable ferromagnetic nanoparticles of adjustable aspect ratio made upon decomposition of organometallic precursors in solution in the presence of a reaction gas and a mixture of organic ligands. The magnetic nanomaterial comprises magnetic nanoparticles of homogeneous size, shape, and magnetic orientation that comprises a magnetic core (24, 34) ferromagnetic at room temerature and/or operating temperatures, and a non-magnetic matrix (26, 36) encapsulating the magnetic core. This magenetic nanomaterial could be used in high frequency integrated circuit applications, such as used in wireless portable electronic devices, to enchance magnetic field confienment and improve passive component performance at MHz and GHz frequency in a variety of passive and active devices, such as transformers, on-chip signal isolation, inductors, and the like. |
| Inventors: |
Renaud, Philippe (Toulouse, FR); Dumestre, Frederic (Toulouse, FR); Chaudret, Bruno (Vigoulet, FR); Fromen, Marie Claire (Toulouse, FR); Casanove, Marie-Jose (Toulouse, FR); Zurcher, Peter (Tempe, AZ, US); Stumpf, Roland (Livermore, CA, US); Amiens, Catherine (Toulouse, FR) |
| Claim: |
1. A thermodynamically stable magnetic nanoparticle comprising a magnetic core that is ferromagnetic at a room/operating temperature and a non-magnetic constituent encapsulating the magnetic core to make the magnetic nanoparticle electrically isolated and protected from atmospheric contaminants with the magnetic nanoparticle having a predetermined adjustable aspect ratio and having a permeability and ferromagnetic resonance suitable for use in MHz-GHz range frequencies. |
| Claim: |
2. A thermodynamically stable magnetic nanoparticle of claim 1 wherein the magnetic core is comprised of a ferromagnetic element selected from the group consisting of Fe, Co, and Ni. |
| Claim: |
3. A thermodynamically stable magnetic nanoparticle of claim 1 wherein the magnetic core is comprised of a binary or tertiary alloy of ferromagnetic element selected from the group consisting of Fe, Co, and Ni. |
| Claim: |
4. A thermodynamically stable magnetic nanoparticle of claim 1 wherein the magnetic core comprises a single magnetic domain. |
| Claim: |
5. A thermodynamically stable magnetic nanoparticle of claim 1 wherein the magnetic nanoparticle has a diameter and length in the range of approximately 2 to 600 nm. |
| Claim: |
6. A thermodynamically stable magnetic nanoparticle of claim 5 wherein the crystalline structure of the ferromagnetic core is hexagonal close packed. |
| Claim: |
7. A thermodynamically stable magnetic nanoparticle of claim 5 wherein the crystalline structure of the ferromagnetic core is body center cubic. |
| Claim: |
8. A thermodynamically stable magnetic nanoparticle of claim 5 wherein the crystalline structure of the ferromagnetic core is face center cubic. |
| Claim: |
9. A thermodynamically stable magnetic nanoparticle of claim 1 wherein the non-magnetic constituent encapsulating the magnetic core is an organic ligand. |
| Claim: |
10. A thermodynamically stable magnetic nanoparticle of claim 9 wherein the organic ligand is a combination of amine and carboxylic acid. |
| Claim: |
11. A thermodynamically stable magnetic nanoparticle of claim 9 wherein the organic ligand is a combination of oleylamine and oleic acid. |
| Claim: |
12. A magnetic nanomaterial comprising an assembly of thermodynamically stable magnetic nanoparticles of claim 1. |
| Claim: |
13. A magnetic nanomaterial of claim 12 wherein each magnetic nanoparticle has an axis of anisotropy aligned with each other magnetic nanoparticle. |
| Claim: |
14. A magnetic nanomaterial of claim 12 wherein each magnetic nanoparticle of the magnetic nanomaterial is of homogeneous size, shape, and magnetic orientation. |
| Claim: |
15. A magnetic nanoparticle of claim 1 for use in passive components in high frequency integrated circuit applications. |
| Claim: |
16. A method for synthesising a magnetic nanoparticle comprising the steps of: providing a first solution comprising a solvent with a carboxylic acid and an amine; adding the first solution to a metal-organic precursor to form a second solution; heating the second solution under pressure for a predetermined period to produce a thermodynamically stable magnetic nanoparticle comprising a magnetic core that is ferromagnetic at a room/operating temperature, and a non-magnetic constituent encapsulating the magnetic core to make the magnetic nanoparticle protected against atmosphere contaminants and electrically isolated with the magnetic nanoparticle having a predetermined adjustable aspect ratio, and having a permeability and ferromagnetic resonance suitable for use in MHz-GHz range frequencies. |
| Claim: |
17. A method for synthesising a magnetic nanoparticle as claimed in claim 16 wherein said providing a first solution step further comprises adding an ether as the solvent. |
| Claim: |
18. A method for synthesising a magnetic nanoparticle as claimed in claim 16 wherein said providing a first solution step further comprises adding an aromatic solvent selected from the group consisting of toluene and anisole. |
| Claim: |
19. A method for synthesising a magnetic nanoparticle as claimed in claim 16 wherein said providing a first solution step further comprises adding an oleic acid as the carbocylic acid. |
| Claim: |
20. A method for synthesising a magnetic nanoparticle as claimed in claim 16 wherein said providing a first solution step further comprises adding an oleylamine as the amine. |
| Claim: |
21. A method for synthesising a magnetic nanoparticle as claimed in claim 16 wherein said adding the first solution step further comprises adding a hydrocarbon metal complex as the metal-organic precursor. |
| Claim: |
22. A method for synthesising a magnetic nanoparticle as claimed in claim 16 wherein said adding the first solution step further comprises adding a cobalt precursor as the metal-organic precursor. |
| Claim: |
23. A method for synthesising a magnetic nanoparticle as claimed in claim 16 wherein said heating step further comprises heating at temperatures between 100 and 250° C. for approximate times between 3 and 60 hours under pressures between 1 and 10 Bars of H2 or H2 containing gas mixtures. |
| Current U.S. Class: |
335084/000 |
| Accession Number: |
edspap.20050200438 |
| Database: |
USPTO Patent Applications |
