2020 Volume 63 Issue 1 Pages 19-24
In this review, our recent study on spin-polarized field electron emitter using Cr(001) surface and Heusler alloy Co2MnGa is described. To obtain a stable and highly spin-polarized electron beam by the field emission, the surface structure of emitters was well-characterized by field ion microscopy (FIM). The atomically clean surface of Cr/W(001) and ⟨100⟩-oriented Co2MnGa emitter realized values of spin polarization of 50% and 60%, respectively, which consistent with spin polarization at the Fermi level predicted theoretically. Especially, the maximum spin polarization of 75% obtained from the Co2MnGa(100) surface is higher than that from other transition metals reported previously. Additionally, it is important for the highly spin-polarized field emitter to keep the clean surface. Our results will promise to equip the spin-polarized field emitters to instruments for spin-resolved analysis.