New Model for Magnetism in Ultrathin fcc Fe on Cu(001)

Abstract

Using soft-x-ray resonant magnetic scattering in combination with first-principles calculations for noncollinear magnetic configurations we present a new model of the magnetism in ultrathin fcc Fe films on Cu(001). We find the presence of blocks with robust magnetic structure, while the relative directions of the moments of different blocks are sensitive to the detailed atomic structure and temperature. The magnetic noncollinearity is directly demonstrated, which has not been possible so far.

Depth-resolved magnetization distribution in ultra thin films by soft X-ray resonant magnetic reflectivity

“…This turns out to be particularly relevant in the soft X-ray range where the reflectivity, measured at large scattering angles, is sensitive to the out-of-plane magnetization [20]. Furthermore, soft X-ray resonant magnetic reflectivity (SXRMR) has been shown to resolve the magnetic structure along the growth axis with in-plane and perpendicular components [21].…”

“…1(a) shows the measurements carried out at room temperature (RT) on a 4 monolayer (ML) thick Fe film deposited on a Cu(001) single crystal surface by pulsed laser deposition and capped by 3 nm of Au [12]. Solid lines represent the reflectivity curves Ip and Im collected in longitudinal geometry using a photon energy tuned close to the Fe L 3 -edge and symbols represent the corresponding asymmetry defined by Figure 1(b) shows data collected at 40 K for a 8 ML Fe film which is known to exhibit an out-of-plane magnetic component [21]. The asymmetries observed for the different magnetization configurations (up to θ = 85 degree) are completely different.…”

“…1(b), R adopts values significantly different to zero at high angles in agreement with the m z sin(θ) product. This allows the separation of the in-and out-of-plane component of the magnetization in an ultra-thin film [21] or in an exchange coupled layer [28].…”

“…The out-of-plane magnetization is probed by magnetizing the sample perpendicular to the sample plane (called here "polar" configuration). Up to now this condition has been realized by moving a permanent magnet close to the sample surface followed by data collection in remanence [20,21,28]. In this case, Ip and Im are obtained by reversing the X-ray helicity.…”

Epitaxially stabilized iron thin films via effective strain relief from steps

“…We chose Fe thin films grown epitaxially on a vicnal Cu(001) surface, whose structural properties have been rarely investigated so far while the growth on a flat Cu(001) are well defined, as a prototypic system to demonstrate the concept proposed avobe. The system in the fcc phase has experimentally and theoretically attracted a great interest over two decades because of its complex magnetic structures [10][11][12][13] . It has been proposed that the top layer ferromagnetically couples to the second layer with antiferromagnetically-coupled underneath layers.…”