Daniel J. Coady, Amanda C. Engler, et al.
ACS Macro Letters
Planar macroscopic magnetic tunnel junctions exhibit well defined zero-bias anomalies when a thin layer of ferromagnetic CoFe(B) nanodots is inserted within a MgO based tunnel barrier. The conductance curves exhibit a single and a double peak, respectively, for antiparallel and parallel alignment of the magnetizations of the electrodes that sandwich the tunnel barrier. This leads to a suppression of the tunneling magnetoresistance near zero bias. We show that the double-peak structure indicates that the zero-bias anomaly is spin split due to a magnetic exchange interaction between the magnetic nanodots and the ferromagnetic electrodes. Using a model based on an Anderson quantum dot coupled to ferromagnetic leads, we show that these results imply the coexistence of a Kondo effect and ferromagnetism. © 2011 American Physical Society.
Daniel J. Coady, Amanda C. Engler, et al.
ACS Macro Letters
A. Ney, R. Rajaram, et al.
Journal of Magnetism and Magnetic Materials
William G. Van der Sluys, Alfred P. Sattelberger, et al.
Polyhedron
John G. Long, Peter C. Searson, et al.
JES