A possible source of spin-polarized electrons: The inert graphene/Ni(111) system

TL;DR

This study demonstrates that a passivated graphene/Ni(111) surface can serve as a stable source of spin-polarized electrons, maintaining polarization even after oxygen exposure, which is promising for spintronic applications.

Contribution

It provides evidence that graphene/Ni(111) systems can produce stable spin-polarized electrons resistant to reactive gas adsorption, a novel insight for spin source design.

Findings

Spin polarization from graphene/Ni(111) is nearly as high as from clean Ni.

Spin polarization remains stable after oxygen exposure.

Passivated graphene/Ni(111) can be used as a durable spin-polarized electron source.

Abstract

We report on an investigation of spin-polarized secondary electron emission from the chemically inert system: graphene/Ni(111). An ordered passivated graphene layer (monolayer of graphite, MG) was formed on Ni(111) surface via cracking of propylene gas. The spin-polarization of the secondary electrons obtained from this system upon photoemission is only slightly lower than the one from the clean Ni surface, but does not change upon large oxygen exposure. These results suggest to use such passivated Ni(111) surface as a source of spin-polarized electrons stable against adsorption of reactive gases.