Hostname: page-component-59f8fd8595-p59nl Total loading time: 0 Render date: 2023-03-22T07:31:02.714Z Has data issue: true Feature Flags: { "useRatesEcommerce": false } hasContentIssue true

Enhanced Magnetic Transition of Core-Shell Cobalt-Platinum Nanoalloys

Published online by Cambridge University Press:  01 February 2011

Jong-Il Park
Affiliation:
Department of Chemistry and School of Molecular Science (BK21), Korea Advanced Institute of science and Technology (KAIST), Taejon, 305-701, Korea.
aNam-Jung Kang
Affiliation:
Department of Chemistry and School of Molecular Science (BK21), Korea Advanced Institute of science and Technology (KAIST), Taejon, 305-701, Korea.
Sang-Min Lee
Affiliation:
Department of Chemistry and School of Molecular Science (BK21), Korea Advanced Institute of science and Technology (KAIST), Taejon, 305-701, Korea.
Sehun Kim
Affiliation:
Department of Chemistry and School of Molecular Science (BK21), Korea Advanced Institute of science and Technology (KAIST), Taejon, 305-701, Korea.
S. J. Oh
Affiliation:
Korea Basic Science Institute (KBSI) Taejon, 305-333, Korea.
H. C. Ri
Affiliation:
Korea Basic Science Institute (KBSI) Taejon, 305-333, Korea.
Jinwoo Cheon
Affiliation:
Department of Chemistry, Yonsei University, Seoul, 120-749, Korea.
Get access

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.

Type
Research Article
Copyright
Copyright © Materials Research Society 2002

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

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).CrossRefGoogle Scholar
2.(a) Jacoby, M., C&E News, 78, 37 (2000). (b) R. Wood, IEEE Trans. Magn. 36, 36 (2000).Google Scholar
3.(a) Sun, S., and Murray, C. B., J. Appl. Phys. 85, 4325 (1999). (b) M. P. Pileni, Phys. Rev. B. 62, 3910 (2000).CrossRefGoogle Scholar
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).CrossRefGoogle Scholar
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).CrossRefGoogle Scholar
6. Liou, S. H., Huang, S., Klimek, E., Kirby, R. D., and Yao, Y. D., J. Appl. Phys. 85, 4334 (1999).CrossRefGoogle Scholar
7. Thielen, M., Kirsch, S., Weinforth, A., Carl, A., and Wassermann, E. F., IEEE Trans. Magn. 34, 1009 (1998).CrossRefGoogle Scholar
8. Crane, E. L., You, Y., Nuzzo, R. G., and Girolami, G. S., J. Am. Chem. Soc. 122, 3422 (2000).CrossRefGoogle Scholar
9. Gu, S., Atanasova, P., Hampden-Smith, M. J., and Kodas, T. T., Thin Solid Films 340, 45 (1999).CrossRefGoogle Scholar
10.(a) Okeya, S., and Kawaguchi, S., Inorganic synthesis 20, 65 (1980). (b) W. P. Weber, G. W. Gokel, Tetrahedron Lett. 13, 1637 (1972).Google Scholar
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.3.0.CO;2-E>CrossRefGoogle Scholar
12. X-ray Powder Diffraction Patterns (“International Centre for Diffraction Data”, Newtown Square, PA) (1996).Google Scholar
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).CrossRefGoogle Scholar
14. Park, J. I., Cheon, J., J. Am. Chem. Soc. 123, 5743 (2001)CrossRefGoogle Scholar