%0 Journal Article
%T Interface states in CoFe2O4 spin-filter tunnel junctions
%A Pavel V. Lukashev
%A J. D. Burton
%A Alexander Smogunov
%A Julian P. Velev
%A Evgeny Y. Tsymbal
%J Physics
%D 2013
%I arXiv
%R 10.1103/PhysRevB.88.134430
%X Spin-filter tunneling is a promising way to generate highly spin-polarized current, a key component for spintronics applications. In this work we explore the tunneling conductance across the spin-filter material CoFe2O4 interfaced with Au electrodes, a geometry which provides nearly perfect lattice matching at the CoFe2O4/Au(001) interface. Using density functional theory calculations we demonstrate that interface states play a decisive role in controlling the transport spin polarization in this tunnel junction. For a realistic CoFe2O4 barrier thickness, we predict a tunneling spin polarization of about -60%. We show that this value is lower than what is expected based solely on considerations of the spin-polarized band structure of CoFe2O4, and therefore that these interface states can play a detrimental role. We argue this is a rather general feature of ferrimagnetic ferrites and could make an important impact on spin-filter tunneling applications.
%U http://arxiv.org/abs/1308.3461v1