Hostname: page-component-848d4c4894-x24gv Total loading time: 0 Render date: 2024-05-21T07:19:22.124Z Has data issue: false hasContentIssue false
  • English
  • Français

Effects of Substrates on the Self-Assembling of FePt Nanocrystals

Published online by Cambridge University Press:  21 March 2011

Min Chen  and
David E. Nikles
Min Chen
Affiliation:
The University of Alabama, Tuscaloosa, Center for Materials for Information Technology, Box 870209, Tuscaloosa, Alabama, 35487-0209, US
David E. Nikles
Affiliation:
The University of Alabama, Tuscaloosa, Center for Materials for Information Technology, Box 870209, Tuscaloosa, Alabama, 35487-0209, USdnikles@mint.ua.edu
Get access

Abstract

Fe48Pt52 nanoparticles were synthesized by the simultaneous chemical reduction of platinum acetylacetonate and thermal decomposition of iron pentacarbonyl. As-prepared the particles were spherical with an average diameter of 3 nm and a polydispersity of less than 5%. The particles were superparamagnetic and had a fcc structure. Highly ordered self-assembled supercrystals of particles were formed in TEM grids by deposition from dispersions in hydrocarbon solvents. Nanoparticles deposited on amorphous carbon-coated and SiO2-coated Cu grids tend to assemble into small domains of hexagonal arrays. Larger domains of hexagonal arrays formed on Si3N4 membrane TEM grids. For thin multilayers, the FePt nanoparticles tends to assemble into hexagonal close-packed lattices (ABABAB stacking). For the thicker multilayers, ABCABC stacking was observed. Small angle X-ray reflectivity of the particles on a Si (100) substrate show highly ordered multiplanar structure with d-spacing of 6.2 nm. The coercivity of self-assembled FePt films strongly depended on the annealing temperature. After annealing at 700°C for 30 minutes, the particles transformed from FCC to “FCT” phase and the coercivity of film increased up to 11570 Oe. However, the particle size increased to 16 nm due to sintering.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 674: Symposia T/U/V – Applications of Ferromagnetic and Optical Materials, Storage and Magnetoelectronics , 2001 , U4.8
Copyright
Copyright © Materials Research Society 2001

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

REFERENCES

1. Weller, D., Moser, A., Folks, L., Best, M. E., Lee, W., Toney, M. F., Schwickert, M., Thiele, J.-U., and Doerner, M. F., IEEE Trans. Magn. 36, 10 (2000)Google Scholar
2. Numazawa, J. and Ohshima, H.. J. Magn. Magn. Mater. 176, 1 (1997).Google Scholar
3. Murdock, E. S., Simmons, R. F., and Davison, R., IEEE Trans. Magn. 28, 3078 (1992).10.1109/20.179719Google Scholar
4. Yogi, T. and Nguyen, T. A., IEEE Trans. Magn. 29, 307 (1993).Google Scholar
5. Lu, P.-L. and Charap, S. H., IEEE Trans. Magn. 30, 4230 (1994).Google Scholar
6. Grochowski, E. and Thompson, D. A., IEEE Trans. Magn. 30, 3797 (1994).Google Scholar
7. New, R. M. H., Pease, R. F. W., and White, R. L., J. Vac. Sci. Technol. B12, 3196 (1994).Google Scholar
8. Lambeth, D. N., Velu, E. M. T., Bellesis, G. H., Lee, L., and Laughlin, D. E., J. Appl. Phys. 79, 4496 (1996).Google Scholar
9. Charap, S. H., Lu, P.-L., and He, Y., IEEE Trans. Magn. 33, 978 (1997).10.1109/20.560142Google Scholar
10. Ohara, P.C., Heath, J.R. and Gelbart, W.M.. Angew. Chem. Int. Ed. Engl. 36, 1078 (1997).Google Scholar
11. Andres, R.P., Bielefeld, J.D., Henderson, J.I., Janes, D.B., Kolagunta, V.R., Kubiak, C.P., Mahoney, W.J. and Osifchin, R.G.. Science 273, 1690 (1996).Google Scholar
12. Bentzon, M.D., Wonterghem, J. Van, Mrup, S., Thölen, A. and Koch, C.J.W.. Phil. Mag. B. 60, 169 (1989).Google Scholar
13. Yin, J.S. and Wang, Z.L.. J. Mater. Res. 14, 503 (1999).10.1557/JMR.1999.0072Google Scholar
14. Taleb, A.; Petit, C.; Pileni, M. P. Chem. Mater. 9, 950. (1997).Google Scholar
15. Sun, S. and Murray, C.B.. J. Appl, Phys. 85, 4325 (1999).Google Scholar
16. Sun, S., Murray, C.B., Weller, D., Folks, L. and Morser, A.. Science. 287, 1989 (2000).Google Scholar
17. County, A., Fermon, C. and Pileni, M.-P.. Adv. Mater. 13, 254 (2001).Google Scholar
18. Zabel, H.. Appl. Phys. A 58, 159 (1994).Google Scholar
19. Alder, B. J.; Hoover;, W. G. and Young, D. A.. J. Chem. Phys., 49, 3688 (1968).10.1063/1.1670653Google Scholar
20. Korgel, B. A. and Fitzmaurice, D.. Phys. Rev. Lett. 80, 3531 (1998).10.1103/PhysRevLett.80.3531Google Scholar
21. Denkov, N. D.; Velev, O. D.; Kralchevsky, P. A., Ivanov, I. B.; Yoshimura, H.; and Nagayama, K.. Langmuir, 8, 3183 (1992).Google Scholar