Spin polarization asymmetry at the surface of chromia

Abstract

We demonstrate boundary spin polarization at the surface of a Cr _2 O _3 single crystal using spin-polarized low-energy electron microscopy (SPLEEM), complementing prior spin polarized photoemission, spin polarized inverse photoemission, and x-ray magnetic circular dichroism photoemission electron microscopy measurements. This work shows that placing a Cr _2 O _3 single crystal into a single domain state will result in net Cr _2 O _3 spin polarization at the boundary, even in the presence of a gold overlayer. There are indications that the SPLEEM contrast for the two polarization states may be different, consistent with scanning tunneling microscopy spectroscopy results obtained from ultrathin films of Cr _2 O _3 .