Hostname: page-component-586b7cd67f-r5fsc Total loading time: 0 Render date: 2024-11-25T15:32:01.194Z Has data issue: false hasContentIssue false

Percolation Structure Observed in Evaporated Nd-Fe-B Films

Published online by Cambridge University Press:  21 February 2011

C.H. Shang
Affiliation:
Department of Materials Science and Engineering, Tsinghua University Beijing 100084, P.R. CHINA
B.X. Liu
Affiliation:
also at Center of Condensed Matter and Radiation Physics, CCAST(World Lab.) Beijing, P.R. CHINA
H.D. Li
Affiliation:
Department of Materials Science and Engineering, Tsinghua University Beijing 100084, P.R. CHINA
Get access

Abstract

Thin alloy films were prepared by evaporating a standard magnetic Nd2Fe14B ingot in a high vacuum e-gun system at roam temperature. The as-deposited films of 50 nm thick were characterized by transmission electron microscopy (TEM) and in situ energy dispersive spectroscopy (EDS). Bright field examination showed that a novel morphology with holes of varied sizes emerged in the films. The hole-like white areas enriched with Nd, and the dark network with Fe. The electron micrograph was digitized by an VAX image processor. An infinite cluster was proved to be a two-dimensional percolating structure at the percolation threshold. The fractal dimension and the percolation threshold were calculated to be 1.90±0.04 and 0.60±0.04, respectively, which are in good consonance with the theoretical predictions. The as-deposited samples were aged at roam temperature for about two months. Enhanced diffusion and solid state reaction induced another percolating networks camposed essentially by Fe7Nd and Nd-riched solid solution.

Type
Research Article
Copyright
Copyright © Materials Research Society 1990

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. Copra, K., Thin Film Phenomena, (New York, McGraw-hill, 1969)Google Scholar
2. see, for example, Deutscher, G., Zallen, R., and Adler, J. (eds.), Percolation, Structure and Processes, Annals of the Isreal Physical Society, Vol.5, (Adam Hilger, Bristel, 1983)Google Scholar
3. Abeles, B., Sheng, P., Coutts, M.D., and Arie, Y., Adv. Phys 24, 407 (1975)Google Scholar
4. Mandelbrot, B.B., The Fractal Geometry of Nature, (W.H. Freeman and Company, San Francisco, 1982)Google Scholar
5. Huang, L.J., Liu, B.X., and Li, H.D., J. Phys. C: Solid State Phys. 21, L51 (1988)Google Scholar
6. Laibowitz, R.B., and Gefen, Y., Phys. Rev. Lett. 53, 380 (1985), and references thereinGoogle Scholar
7. Garfunkel, G.A. and Weissman, M.B., Phys. Rev. Lett. 55, 796 (1985)Google Scholar
8. Buschow, K.H.J., Mater. Sci. Rep. 1, 1 (1986)Google Scholar
9. Voss, R.F., Laibowitz, R.B., and Alessandrini, E.Y., Phys Rev. Lett. 49, 1441 (1982); and D. Stauffer, Phys. Rep. 54, 1 (1979)Google Scholar
10. Reich, G.R., and Leath, P.L., J. Stat. Phys. 19, 611 (1978)Google Scholar
11. Stauffer, D., Z. Phys. B 37, 89 (1980)Google Scholar