1 research outputs found
Magnetic Patterning by Electron Beam-Assisted Carbon Lithography
We
report on the proof of principle of a scalable method for writing
the magnetic state by electron-stimulated molecular dissociative adsorption
on ultrathin Co on Re(0001). Intense microfocused low-energy electron
beams are used to promote the formation of surface carbides and graphitic
carbon through the fragmentation of carbon monoxide. Upon annealing
at the CO desorption temperature, carbon persists in the irradiated
areas, whereas the clean surface is recovered elsewhere, giving origin
to chemical patterns with nanometer-sharp edges. The accumulation
of carbon is found to induce an in-plane to out-of-plane spin reorientation
transition in Co, manifested by the appearance of striped magnetic
domains. Irradiation at doses in excess of 1000 L of CO followed by
ultrahigh vacuum annealing at 380 °C determines the formation
of a graphitic overlayer in the irradiated areas, under which Co exhibits
out-of-plane magnetic anisotropy. Domains with opposite magnetization
are separated here by chiral Neél walls. Our fabrication protocol
adds lateral control to spin reorientation transitions, permitting
to tune the magnetic anisotropy within arbitrary regions of mesoscopic
size. We envisage applications in the nano-engineering of graphene-spaced
stacks exhibiting the desired magnetic state and properties