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Enhanced Magnetic Transition of Core-Shell Cobalt-Platinum Nanoalloys

  • Jong-Il Park (a1), aNam-Jung Kang (a1), Sang-Min Lee (a1), Sehun Kim (a1), S. J. Oh (a2), H. C. Ri (a2) and Jinwoo Cheon (a3)...

Abstract

Synthesis of ‘solid solution’ and ‘core-shell’ types of well defined Co-Pt based nanoalloys smaller than 10nm have been achieved by redox transmetalation reactions. This redox transmetalation are selectively observed only if the redox potential between two metals is favorable. The composition of the magnetic alloys can also be tuned by adjusting the ratio of reactants. Annealed core-shell nanoparticles transformed into mixed nanoalloys with face centered tetragonal (fct) structures, which show large coercivity and ferromagnetism at room temperature. These nanoparticles can potentially be used as an independent single magnetic bit of tera-bit information storage. Also, this kind of redox transmetalation reaction can be utilized as a general process to synthesize various types of nanoalloys with controlled composition in a selective fashion.

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1.(a) Leslie-Pelecky, D. L., and Rieke, R. D., Chem. Mater. 8, 1770 (1996). (b) A. P. Alivisatos, J. Phys. Chem. 100, 13226 (1996).
2.(a) Jacoby, M., C&E News, 78, 37 (2000). (b) R. Wood, IEEE Trans. Magn. 36, 36 (2000).
3.(a) Sun, S., and Murray, C. B., J. Appl. Phys. 85, 4325 (1999). (b) M. P. Pileni, Phys. Rev. B. 62, 3910 (2000).
4.(a) Ely, T. O., Pan, C., Amiens, C., Chaudret, B., Dassenoy, F., Lecante, P., Casanove, M.-J., Mosset, A., Respaud, M., and Broto, J. CM., J. Phys. Chem. B 104, 695 (2000). (b) E. E. Carpenter, C. T. Seip, and C. J. O'Connor, J. Appl. Phys. 85, 5184 (1999).
5.(a) Carpenter, E. E., Sims, J. A., Wienmann, J. A., Zhou, W. L., and O'Connor, C. J., J. Appl. Phys. 87, 5615 (2000). (b) S. Sun, C. B. Murray, D. Weller, L. Folks, and A. Moser, Science 287, 1989 (2000).
6. Liou, S. H., Huang, S., Klimek, E., Kirby, R. D., and Yao, Y. D., J. Appl. Phys. 85, 4334 (1999).
7. Thielen, M., Kirsch, S., Weinforth, A., Carl, A., and Wassermann, E. F., IEEE Trans. Magn. 34, 1009 (1998).
8. Crane, E. L., You, Y., Nuzzo, R. G., and Girolami, G. S., J. Am. Chem. Soc. 122, 3422 (2000).
9. Gu, S., Atanasova, P., Hampden-Smith, M. J., and Kodas, T. T., Thin Solid Films 340, 45 (1999).
10.(a) Okeya, S., and Kawaguchi, S., Inorganic synthesis 20, 65 (1980). (b) W. P. Weber, G. W. Gokel, Tetrahedron Lett. 13, 1637 (1972).
11. Park, J. I., Kang, N. J., Oh, S. J., Ri, H. C., and Cheon, J., ChemPhysChem 3, (2002) (in press). (a) TB = 10 K and Hc = 260 Oe for 2.2 nm Co, (b) TB = 100 K and Hc = 470 Oe for 6.4 nm Co, (c) TB = 20 K and Hc = 370 Oe for 4.0 nm Co nanoparticles, respectively.
12. X-ray Powder Diffraction Patterns (“International Centre for Diffraction Data”, Newtown Square, PA) (1996).
13.(a) Schmid, G., Lehnert, A., Malm, J. O., Bovin, J. O., Angew. Chem. Int. Ed. Engl. 30, 874 (1991). (b) G. Schmid, H. West, H. Mehles, A. Lehnert, Inorg. Chem. 36, 891 (1997). (c) T. Wang, N. Toshima, J. Phys. Chem. B 101, 5301 (1997).
14. Park, J. I., Cheon, J., J. Am. Chem. Soc. 123, 5743 (2001)

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