On the dynamics of the reentrant spin-glass state of the Fe{sub 100−x}Zr{sub x} (x = 9, 10) amorphous alloys
- Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife-Pernambuco (Brazil)
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455 (United States)
Low temperature magnetization (M) and ac susceptibility (χ{sub ac}) data were used to investigate the reentrant spin-glass state in lengths of melt-spun ribbons of Fe{sub 100−x}Zr{sub x} (x = 9, 10) amorphous alloys. The temperature range investigated was from 2 to 300 K, while the applied magnetic field H was varied in the range of ±85 kOe. The magnetic properties were found to be strongly influenced by the sample composition despite the fact that the amount of Fe varies by 1 at. %. For instance, the Curie temperature (T{sub C}) is reduced from 232.5 K to 213.0 K with decreasing Fe concentration, while M for the lower Fe concentration, measured at the highest applied magnetic field (H = 85 kOe) was nearly double the value for that of the higher; the coercivity in the ferromagnetic regime is reduced by a factor close to five when x is increased from 9 at. % to 10 at. %. The ac susceptibility measured for frequencies f in the range of 10–10{sup 4 }Hz showed a sharp drop in the magnitude of the in-phase contribution (χ{sub ac}{sup ′}) and a peak at the out-of-phase component (χ{sub ac}{sup ″}), which shifts to higher temperatures with increasing values of f. The Voguel-Fulcher law applied to the χ{sub ac}{sup ″} data yielded an activation energy E{sub a}/k{sub B} = 21.3 K (40.1 K), the glassy temperature T{sub G} = 15.5 K (38.2 K), and a relaxation time τ{sub 0}=9.1×10{sup −7} s (8.3×10{sup −7} s), for the sample with x = 10 (x = 9). A plot of χ{sub ac}{sup ″}vsχ{sub ac}{sup ′} for a broad range of T and f yielded a broad maximum near the glassy temperature T{sub G} for both sample concentrations.
- OSTI ID:
- 22410139
- Journal Information:
- Journal of Applied Physics, Vol. 117, Issue 17; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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