Spin Polarization of Field-Emitted Electrons from Monocrystalline Nickel

Abstract

Field-emitted electrons from magnetized monocrystalline Ni tips at 80 K have been investigated for spin polarization. A maximum polarization of 13% was observed. The predominant direction of the spins was parallel to the external magnetic field for electrons emitted around $〈100〉$, $〈110〉$, and $〈137〉$ and antiparallel for electrons emitted around $〈111〉$. Direction and degree of spin polarization is discussed in the context of band-structure theory and recent model calculations of field emission from $3d$ transition elements.