ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Magnetic aftereffects (MAEs) of the initial reluctivity have been measured over times of 1–106 s in the as-quenched state of amorphous alloy Fe40Ni40P14B6 at 500 K. A considerable decrease in the relaxation amplitude observed for times t〉103–10 s has been interpreted in terms of a superposition of two different mechanisms resulting from (i) quasi-reversible, local rearrangements of two-level systems, and (ii) irreversible, wide-range order relaxation due to the migration of free volumes.2 Here we report on the results obtained from fractal analysis of the short-time MAE region (t(approximately-less-than)200 s). Fitting of the stretched exponential,3 exp[−(t/τ)ρ], (0〈β〈1), to the experimental data yielded values of ρ in the range 0.15–0.30. This implies a spectral (fracton) dimension d˜ of 0.3–0.6 for this alloy. In terms of a postulated ultrametric distribution of random energy barriers, this means a hierarchy with a low degree of ramification (Z∼1.2).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.342315
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