Spin-Density Wave in Ultrathin Fe Films on Cu(100)

Abstract

For Fe films epitaxially grown on Cu(100) at 300 K, the total magnetic moment as a function of film thickness and its temperature dependence have been investigated in situ with a multitechnique approach. The results exclude the collinear type-1 antiferromagnetic configuration as the magnetic structure for face-centered-cubic Fe films on Cu(100). It is proposed that a spin-density-wave state is responsible for the magnetic structure.

Temperature Dependence of the Surface Anisotropy of Fe Ultrathin Films on Cu(001)

“…One might speculate whether the formation of bcc crystallites during warming, as have been seen with high resolution STM on RT grown Fe films [21], reduce the perpendicular anisotropy by gradually making the fcc film more bcclike. This idea is supported by recent experiments showing drastic changes of the morphology of a RT grown fcc-Fe film on Cu(001) after cooling and subsequent warming up to 300 K, ascribed to a transition of the film towards bcc structure [14]. Thermally activated interdiffusion between Fe and Cu, which is known to alter the magnetic anisotropy energy [22], does not have to be considered here since it is found to be negligible below 300 K [23].…”

“…In the same thickness region, the easy axis of magnetization is reoriented out of the film plane [10], ascribed to dominating surface anisotropy contributions [11,12]. The morphology sensitively depends on the growth temperature [13] and the thermal treatment after growth [14]. We focus on low temperature grown films since they exhibit enhanced surface roughness compared to films grown at room temperature [13,15].…”

Exchange interactions, spin waves, and transition temperatures in itinerant magnets

“…In the limit of one-monolayer thickness of the film, one can realize a true two-dimensional magnet on a non-magnetic substrate. Equally interesting is the behaviour of magnetic properties with increasing film thickness, as can be documented by the intensively studied Fe films on an fcc Cu(001) substrate that display a variety of structures and magnetic configurations [132,133]. Their understanding in terms of ab initio techniques is a difficult task even concerning the ground-state properties [134].…”

Reduced-dimensionality-induced helimagnetism in iron nanoislands

“…This is also corroborated by the prediction of an SH in free-standing monolayers (MLs) of bcc-Fe(110) in theory 12 . In view of a change of spin order, driven by subtle structural changes, the Fe/Cu(001) system is a prototypical example for extended Fe layers [22][23][24] . We exploit that Fe in bridge-site-stacking is stabilized only in nm-small BLr Fe islands on Cu(111), which plays a pivotal role of the formation of the SH reported here.…”