Magnetic properties of ferromagnetic γ-Fe films on Cu (111)

Abstract

Epitaxial f.c.c. γ‐Fe‐films on Cu (111) with a well‐defined structure are measured magnetometrically. Layer‐grown as well as island‐grown films prepared with a film thickness between 3 and about 85 Å, are found to be ferromagnetic with a magnetic moment of (0.58 ± 0.13) μB/atom. The temperature dependence of the anisotropy field differs fundamentally for layer‐ and islandgrown films. The existence of ferromagnetic γ‐Fe‐films, which seems to be controversal to the antiferromagnetism of γ‐Fe‐precipitates, can be explained by the epitaxial expansion of the lattice parameter and will be discussed in terms of different concepts of the magnetic order in γ‐Fe.

Magnetic Moment of fcc Fe(111) Ultrathin Films by Ultrafast Deposition on Cu(111)

“…This means that by thermal growth, the net magnetic moment of the fcc films is about 4 to 5 times smaller than that of the bcc films. Assuming the typical moment of 2.2m B for the transformed bcc films, we estimate the net moment of the TD films in the fcc regime to be about 0.5m B , which is consistent with previous results from the copper capped films [10] and the films supported by a stepped substrate [11].…”

“…The net moment of Fe films falls immediately [8] after they become fcc-like (5 to 10 ML) [7]. On the (111) surface, the Fe films appear to have near isotropic fcc structure [9] but magnetic measurements on films capped by copper [10] as well as on films supported by a stepped substrate [11] indicate that Fe possesses a significantly smaller net moment of about 0.5m B . Therefore, the very fundamental question, i.e., whether an isotropic fcc Fe system can be high-moment ferromagnetic or not, has yet to be answered experimentally.…”

Growth, structure, and magnetism of fcc Fe ultrathin films on Cu(111) by pulsed laser deposition

“…For this we make two basic assumptions: ͑1͒ the Kerr intensity is proportional to the magnetization of both fcc and bcc films; ͑2͒ the transformed bcc Fe films possess the magnetic moment of the bulk ␣-Fe, i.e., 2.2 B . In our previous work we have verified that the first assumption is true, 9 while the second assumption appears to be also reasonable since the magnetic moment of bcc Fe is much less sensitive to the change of the lattice parameters as compared to that of the fcc Fe.…”

“…In contrast the Cu͑111͒ allows the growth of a nearly isotropic fcc Fe below approximately 3-4 ML. 8 But different experiments on copper capped films 9 and films grown on stepped surface 10 using thermal deposition indicate a small moment for the Fe of the order of 0.5 B . It is thus of great interest to study whether high-moment ferromagnetic Fe/Cu films with a true fcc structure can be achieved.…”

Spin-reorientation transition inFexNi1−xalloy films

“…Such a behavior has been indeed observed for a variety of systems such as Fe/Cu͑111͒, Fe/Ag͑100͒, and Co/Au͑111͒. [1][2][3][4] The properties of Ni and Fe films on a Cu͑100͒ substrate have been extensively studied. Both systems show a spin reorientation transition ͑SRT͒ as a function of thickness.…”