Enhanced Magnetic Hybridization of a Spinterface through Insertion of a Two-Dimensional Magnetic Oxide Layer

Abstract

Interfaces between organic semiconductors and ferromagnetic metals offer intriguing opportunities in the rapidly developing field of organic spintronics. Understanding and controlling the spin-polarized electronic states at the interface is the key toward a reliable exploitation of this kind of systems. Here we propose an approach consisting in the insertion of a two-dimensional magnetic oxide layer at the interface with the aim of both increasing the reproducibility of the interface preparation and offering a way for a further fine control over the electronic and magnetic properties. We have inserted a two-dimensional CrO layer at the C/Fe(001) interface and have characterized the corresponding morphological, electronic, and magnetic properties. Scanning tunneling microscopy and electron diffraction show that the film grows well-ordered both in the monolayer and multilayer regimes. Electron spectroscopies confirm that hybridization of the electronic states occurs at the interface. Finally, magnetic dichroism in X-ray absorption shows an unprecedented spin-polarization of the hybridized fullerene states. The latter result is discussed also in light of an ab initio theoretical analysis.

Tailoring the magnetic ordering of the Cr4O5/Fe(001) surface via a controlled adsorption of C60 organic molecules

“…Notably, the net magnetization of the Cr atoms in the oxide layer is always opposite to the underlying Fe one, as in absence of molecules, confirming the antiferromagnetic coupling between the overlayer and the substrate evidenced by the experiments [14]. Indeed, also in the configurations The magnetic moment of the C atoms is three orders of magnitude smaller than that of the Cr atoms and its sign depends on the adsorption configuration.…”

“…In recent works [14][15][16] some of us focused on the C 60 /Fe(001) interface, both on the experimental and theoretical viewpoint. We demonstrated that the induced magnetic properties on the molecules depend on the spin polarization of the substrate states interacting with the molecule itself and by their decay toward vacuum.…”

Room temperature magnetism of ordered porphyrin layers on Fe

“…[22][23][24] We identify in the passivation of the surface a viable strategy for tuning the molecular coupling. 25,26 Some earlier attempts are acknowledged, where ultrathin oxides [27][28][29] or graphene [30][31][32] were specifically used to change the nature of the interaction between the molecules and the substrate to indirect superexchange mediated by the interlayer. For most of these systems, however, scarce structural information about the molecular layers is reported.…”

Effects of the introduction of a chromium oxide monolayer at the C60/Fe(001) interface

“…Selected PES spectra related to 1 molecular layer of C 60 on Fe(001), Fe(001)-p(1 Â 1)O, and Cr 4 O 5 =Fe have already been discussed in previous publications. 8,12 In Fig. 2, we present a set of normal emission PES spectra related to the C 60 =Cr 4 O 5 =Fe system, by reporting them as a function of molecular coverage.…”

“…We have furthermore studied the magnetic hybridization at such interfaces and at the interface between a C 60 and a Cr 4 O 5 monolayer stabilized onto the Fe(001) surface. 12 Those investigations lead to the observation of spin-polarized fullerene states in all cases.…”