Suppression of magnetic coercivity in thin Ni films near the percolation threshold

초록

We have studied the behavior of magnetic coercivity H<inf>c</inf>, across the geometric percolation in MBE grown epitaxial Ni films. By increasing a Cu buffer layer thickness, the morphology of Ni films changes from a collection of finite clusters to a single infinite cluster, while all other structural parameters remain constant. H<inf>c</inf> drops rapidly near the geometric percolation threshold. Atomic Force Microscopy shows the presence of an infinite cluster with fractal dimension D<inf>c</inf> ∼ 1.9, in agreement with percolation theory. The suppression of H<inf>c</inf> may be due to increased domain wall motion within the infinite cluster. © 1999 Published by Elsevier Science B.V. All rights reserved.

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