Method of maintaining particle size

Metal treatment – Process of modifying or maintaining internal physical... – Treating loose metal powder – particle or flake

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C148S105000, C148S121000

Reexamination Certificate

active

07608158

ABSTRACT:
The present invention includes particle compositions and methods of fabrication that prevent agglomeration, thereby maintaining particle size and/or shape. Particles of the present invention were prepared after embedding chemically disordered metal-containing particles in at least one salt to form a dispersion. The dispersion of particles in salt was treated to temperatures of at least about 500 degrees Centigrade for several hours. Particles were easily recovered from the dispersion and did not agglomerate. The particles were also absent contaminating salts after performing simple washing and/or rinsing steps. Structural, compositional and/or magnetic characterizations of the metal-containing particles confirmed that they had not agglomerated. When particles with an fcc structure formed a dispersion with at least one salt, the method yielded the formation of particles having an fct structure with high magnetic anisotropy and without a substantial change in size and/or shape. When desired, however, particles shape and/or size may be changed.

REFERENCES:
K. Elkins, D. Li, et al, Monodisperse face-centered tetragonal FePt nanoparticles with giant coercivity, J. Phys. D: Appl. Phys. 2005, vol. 38, p. 2306-2309.
K.E. Elkins et al, Ultrafine FePt Nanoparticles Prepared by the Chemical Reduction Method, Nano Letters, 2003, vol. 3, No. 12, p. 1647-1649.
Y. Ding et al, Sintering prevention and phase transformation of FePt nanoparticles, Journal of Magnetism and Magnetic Materials, 2004, vol. 284, 9. 336-341.
T. Tsuzuki and P.G. McCormick, Mechanochemical synthesis of nanoparticles, Journal of Materials Science, 2004, vol. 39, p. 5143-5146.
Maeda, T., et. al., Reduction of ordering temperature of an FePt-ordered alloy by addition of Cu, Applied Physics Letters, American Institute of Physics, 2002, 2147-2149, V. 80, No. 12.
Carpenter, E.E., et. al., Magnetism of nanophase metal and metal alloy particles formed in ordered phases, Journal of Applied Physics, American Institute of Physics, 1999, 5184-5186, V. 85, No. 8.
Ulmeanu, M., et. al., Composition-dependent ratio of orbital-to-spin magnetic moment in structurally disordered Fex Pt1-x nanoparticles, Physical Review B 69, The American Physical Society, 2004, 054417-1 -054417-5.
Yu, A.C.C., et. al., Fabrication of monodispersive FePt nanoparticle films stabilized on rigid substrates, Applied Physics Letters, American Institute of Physics, 2003, 4352-4354, V. 82, No. 24.
Momose, S., et. al., Magnetic properties of magnetically isolated L10-FePt nanoparticles, Applied Physics Letters, American Institute of Physics, 2004, 1748-1750, V. 85, No. 10.
Sato, K., et. al., Preparation and properties of ferromagnetic FePt dispersion, Science Direct, Journal of Magnetism and Magnetic Materials, 2004, 1-4.
Jeyadevan, B., et. al., Direct Synthesis of fct-FePt Nanoparticles by Chemical Route, Japanese Journal of Applied Physics, the Japan Society of Applied Physics, 2003, L350-L352, V. 42, Part 2, No. 4A.
Jeyadevan, B., et. al., Towards direct synthesis of fct-FePt nanoparticles by chemical route, Journal of Applied Physics, American Institute of Physics, 2003, 7574-7576, V. 93, No. 10.
Held, G.A., et. al., Competing interactions in dispersions of superparamagnetic nanoparticles, Physical Review B, The American Physical Society, 2001, 012408-1-012408-4, V. 64.
Kang, S., et. al., Easy axis alignment of chemically partially ordered FePt nanoparticles, Applied Physics Letters 86, American Institute of Physics, 2005, 062503-1-062503-3.
Thomson, T., et.al., FePt magnetic nanoparticles: a Sans study of agglomeration effects, Scientific Highlights Materials Science, 50-51.
Ding, Y., et. al., Sintering prevention and phase transformation of FePt nanoparticles, Science Direct, Journal of Magnetism and Magnetic Materials 284, 2004, 336-341.
Kang, S., et. al., Reduction of the fcc to L10 Ordering Temperature for Self-Assembled FePt Nanoparticles Containing Ag, Nano Letters, American Chemical Society, 2002, 1033-1036, V. 2, No. 10.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Method of maintaining particle size does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method of maintaining particle size, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of maintaining particle size will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-4107931

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.