Direct observation of a positive spin polarization at the (111) surface of magnetite

作者：Pratt A^*; Kurahashi M; Sun X; Gilks D; Yamauchi Y

来源：Physical Review B, 2012, 85(18): 180409.

DOI：10.1103/PhysRevB.85.180409

We report direct experimental evidence showing that the spin polarization P at the surface of clean Fe3O4(111) is positive at the Fermi level E-F as measured using a spin-polarized metastable helium beam [He(2(3)S)] and a bulk Fe3O4(111) single crystal under high magnetic fields of up to 4 T. Density functional theory calculations confirm this surprising result, which has significant implications for the incorporation of magnetite in spintronic device applications. We also find that passivation of the surface with hydrogen does not enhance P(E-F), unlike for the Fe3O4(001) surface, where a marked increase is observed.

• 出版日期2012-5-25
• 单位中国科学技术大学