Effect of Orbital Hybridization on Spin-Polarized Tunneling across Co/C60Interfaces.
The interaction between ferromagnetic surfaces and organic semiconductors leads to the formation of hybrid interfacial states. As a consequence, the local magnetic moment is altered, a hybrid interfacial density of states (DOS) is formed, and spin-dependent shifts of energy levels occur. Here, we show that this hybridization affects spin transport across the interface significantly. We report spin-dependent electronic transport measurements for tunnel junctions comprising C60molecular thin films grown on top of face-centered-cubic (fcc) epitaxial Co electrodes, an AlOxtunnel barrier, and an Al counter electrode. Since only one ferromagnetic electrode (Co) is present, spin-polarized transport is due to tunneling anisotropic magnetoresistance (TAMR). An in-plane TAMR ratio of approximately 0.7% has been measured at 5 K under application of a magnetic field of 800 mT. The magnetic switching behavior shows some remarkable features, which are attributed to the rotation of interfacial magnetic moments. This behavior can be ascribed to the magnetic coupling between the Co thin films and the newly formed Co/C60hybridized interfacial states. Using the Tedrow-Meservey technique, the tunnel spin polarization of the Co/C60interface was found to be 43%.
NanoElectronics (NE) Group, MESA+ Institute for Nanotechnology, University of Twente , P. O. Box 217, Enschede 7500AE, The Netherlands.
Kai
K
Wang
NanoElectronics (NE) Group, MESA+ Institute for Nanotechnology, University of Twente , P. O. Box 217, Enschede 7500AE, The Netherlands.
Elia
E
Strambini
NanoElectronics (NE) Group, MESA+ Institute for Nanotechnology, University of Twente , P. O. Box 217, Enschede 7500AE, The Netherlands.
Johnny G M
JGM
Sanderink
NanoElectronics (NE) Group, MESA+ Institute for Nanotechnology, University of Twente , P. O. Box 217, Enschede 7500AE, The Netherlands.
Thijs
T
Bolhuis
NanoElectronics (NE) Group, MESA+ Institute for Nanotechnology, University of Twente , P. O. Box 217, Enschede 7500AE, The Netherlands.
Wilfred G
WG
van der Wiel
NanoElectronics (NE) Group, MESA+ Institute for Nanotechnology, University of Twente , P. O. Box 217, Enschede 7500AE, The Netherlands.
Michel P
MP
de Jong
C60; Co/C60 hybrid interfacial states; hybrid interfacial density of states; interfacial magnetic moments; organic spintronics; spin-dependent density of states; spinterfaces; tunneling anisotropic magnetoresistance (TAMR)