Atomically Resolved Spin-Dependent Tunnelling on the Oxygen-Terminated   Fe3O4 (111)
  We employ spin-polarized (SP) STM to study the spin-dependent tunneling between a magnetite (111) sample and an antiferromagnetic tip through a vacuum barrier at room temperature. Atomic scale STM images show significant magnetic contrast corresponding to variations in the local surface states induced by oxygen vacancies. The estimated variations in tunneling magnetoresistance (TMR) of 250% suggest that the spin-transport properties are significantly altered locally by the presence of surface defects. 
N. Berdunov, S. Murphy, G. Mariotto, I. V. Shvets