Magnetic Properties of Nanocrystalline Fe_xCu_1-xAlloys Prepared by Ball Milling

Superferromagnetism in mechanically alloyed fcc Fe23Cu77with bimodal cluster size distribution

“…A rather similar spectrum, but with a less intense central part, is seen for sputtered Fe 26 Cu 74 (T C ∼ 240 K) at 160 K, in a temperature range where the field varies strongly with T [10]. Rather similar fields, although somewhat larger, with values of 22 T, 20 T, 21.6 T, and 22 T are reported at 77 K for MA Fe 20 Cu 80 [36], Fe 25 Cu 75 [19], and Fe 30 Cu 70 (T C ∼ 380 K [30]) samples and at 83 K for MA Fe 30 Cu 70 (T C ∼ 300 K [31]), respectively. By contrast, much smaller mean fields of ∼7 T and ∼8 T at 4.2 K are obtained from figure 4 of [9] for sputtered Fe 20 Cu 80 at.% and Fe 30 Cu 70 at.% respectively.…”

“…Values in this range are reported in analogous studies of MA Fe-Cu alloys: a moment of 2.3-2.4 μ B /Fe atom is reported by Eilon et al [19] for Fe 25 Cu 75 . Mashimo et al [34] give 2.07 μ B for MA and shock consolidated Fe 30 Cu 70 , Mazzone et al [20] give 2.26 μ B for as-milled Fe 30 Cu 70 , Yousif et al [36] give an experimental value of 3.05 μ B and a theoretical value of 2.65 μ B for Fe 20 Cu 80 . A value of 2.23 μ B /Fe atom is obtained for Fe x Cu 100−x from μ = 2.85(x − 5)/x μ B /Fe atom by Bove et al [64].…”