Spin-glass-like static and dynamic properties of mechanically alloyed Fe–Re–Cr

• Published in: Journal of applied physics Vol. 87; no. 9; pp. 6534 - 6536
• Main Authors: De Toro, J. A., López de la Torre, M. A., Arranz, M. A., Riveiro, J. M., Martı́nez, J. L.
• Format: Journal Article
• Language: English
• Published: 01.05.2000
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.372761

We report the observation of spin-glass-like features in a Fe61Re30Cr9 sample obtained after high energy milling for 460 h. X-ray diffraction showed a broad nanocrystalline peak. The zero-field-cooled and field-cooled magnetization curves exhibited a clear irreversibility, the former showing a relatively sharp maximum for low fields at Tmax≈60 K. In addition, the temperature dependence of the magnetic AC susceptibility (χac) also showed a peak at approximately the same temperature. The frequency sensitivity of such maximum (p=ΔTmax/TmaxΔ log w≈0.02) is small compared to that of typical superparamagnets. However, we discuss the insufficiency of this set of phenomena to assert the existence of a true spin-glass transition and propose the blocking of interacting ferromagnetic nanoparticles as the origin of the observed behavior. The effect of annealing, rendered into nanocrystallite growth, on the χac maximum is studied in an attempt to test this explanation.