US5456986A
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Magnetic metal or metal carbide nanoparticles and a process for forming same
Assignee: Carnegie Mellon University
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Filing: 1993-06-30
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Granted: 1995-10-10
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Expires: 2013-06-30
Abstract
Abstract A magnetic metal or metal carbide nanoparticle is provided having a carbon coating. The nanoparticle has a diameter in the range of approximately 5 to 60 nm, and may be crystalline or amorphous. The magnetic metal or metal carbide nanoparticle is formed by preparing graphite rods which are packed with a magnetic metal oxide. The packed graphite rods are subjected to a carbon arc discharge to produce soot containing magnetic metal or metal carbide nanoparticles and non-magnetic species. The soot is subsequently subjected to a magnetic field gradient to separate the magnetic metal or metal carbide nanoparticles from the non-magnetic species. Ferromagnetic or paramagnetic compounds are made by starting with graphite rods packed with the oxides of iron, cobalt, nickel and manganese bismuth, or a rare earth element excluding lanthanum, lutetium and promethium, or a paramagnetic transition metal.
Inventors
- 👤 Sara Majetich
- 👤 Michael McHenry
- 👤 Joseph Artman
- 👤 Stuart Staley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:14
CPC Classifications
B; B22; B22F; B22F9/00; B22F9/16; B22F9/18; B22F9/20; H; H01; H01F; H01F1/00; B22F1/00; B22F1/05; B22F1/054; B22F1/08; B22F1/16; B22F9/02; B22F9/14; B82; B82Y; B82Y25/00; B82Y30/00; C; C01; C01B; C01B32/00; C01B32/90; C01B32/907; H01F1/0036; H01F1/0045; H01F1/0054; B22F2999/00; C01P; C01P2002/00; C01P2002/02; C01P2002/70; C01P2004/00; C01P2004/01; C01P2004/04; C01P2004/60; C01P2004/64; C01P2004/80; C01P2006/00; C01P2006/42; C22; C22C; C22C26/00; C22C2026/001; Y; Y10; Y10S; Y10S977/00; Y10S977/70; Y10S977/734; Y10S977/742; Y10S977/832; Y10S977/838; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2993; Y10T428/30
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
30 words
A magnetic metal or magnetic metal carbide nanoparticle having a coating consisting essentially of elemental carbon, said nanoparticle having a diameter in the range of approximately 5 to 60 nm.
Claim 2
Dependent Claim
30 words
A magnetic metal or magnetic metal carbide nanoparticle having a coating consisting essentially of elemental carbon, said nanoparticle having a diameter in the range of approximately 5 to 60 nm.
Claim 3
Dependent Claim
62 words
The nanoparticle of claim 1 wherein said nanoparticle is one of a crystallite having a diameter in the range of approximately 5 to 60 nm, an amorphous particle having a diameter in the range of approximately 5 to 60 nm or a nanotube having a length less than 1 cm and having a diameter in the range of 5 to 60 nm.
Claim 4
Dependent Claim
16 words
The nanoparticle of claim 1 wherein said nanoparticle is one of a paramagnetic or ferromagnetic compound.
Claim 5
Dependent Claim
22 words
The nanoparticle of claim 3 wherein said ferromagnetic compound is selected from the group consisting of iron, cobalt, nickel, and manganese bismuth.
Claim 6
Dependent Claim
26 words
The nanoparticle of claim 3 wherein said paramagnetic compound is selected from the group consisting of the rare earth metals except for lanthanum, lutetium and promethium.
Claim 7
Dependent Claim
70 words
A magnetic metal or magnetic metal carbide nanoparticle formed by preparing graphite rods, said graphite rods being packed with a magnetic metal oxide, subjecting said packed graphite rods to a carbon arc discharge to produce soot containing magnetic metal or magnetic metal carbide nanoparticles and non-magnetic species, and applying a magnetic field gradient to said soot to separate said magnetic metal or magnetic metal carbide nanoparticles from said non-magnetic species.
Claim 8
Dependent Claim
70 words
A magnetic metal or magnetic metal carbide nanoparticle formed by preparing graphite rods, said graphite rods being packed with a magnetic metal oxide, subjecting said packed graphite rods to a carbon arc discharge to produce soot containing magnetic metal or magnetic metal carbide nanoparticles and non-magnetic species, and applying a magnetic field gradient to said soot to separate said magnetic metal or magnetic metal carbide nanoparticles from said non-magnetic species.
Claim 9
Dependent Claim
16 words
The nanoparticle of claim 6 wherein said nanoparticle is one of a paramagnetic or ferromagnetic compound.
Claim 10
Dependent Claim
22 words
The nanoparticle of claim 7 wherein said ferromagnetic compound is selected from the group consisting of iron, cobalt, nickel, and manganese bismuth.
Claim 11
Dependent Claim
26 words
The nanoparticle of claim 7 wherein said paramagnetic compound is selected from the group consisting of the rare earth metals except for lanthanum, lutetium and promethium.
Claim 12
Dependent Claim
25 words
The nanoparticle of claim 7 wherein said nanoparticle is segregated by magnetic moment per volume by varying the magnetic field gradient applied to said soot.
References Cited (Backward Citations)
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