Impact of Heisenberg Coupling Strength of Ferromagnetic Electrodes on Temporal and Spatial Properties of Magnetic Tunnel Junction based Molecular Spintronics Devices (MTJMSD)

Magnetic tunnel junction based molecular spintronics devices (MTJMSD) were fabricated by bridging single-molecule magnets (SMMs) across the insulating tunnel barrier on prefabricated magnetic tunnel junction^1. The SMMs produced strong exchange coupling between the ferromagnetic electrodes. We used Monte Carlo (MC) simulations based on the Ising model analog of MTJMSD to investigate the effect of ferromagnetic electrodes on magnetic and physical properties of the device. We varied the Heisenberg coupling in the MTJMSD’s ferromagnetic electrodes as well as their Curie temperature. Here we will discuss: 1) The impact of ferromagnetic type on MTJMSD magnetization equilibrium state over time. 2) The effect of varying the molecular coupling strength and the ferromagnetic electrode's Heisenberg exchange coupling simultaneously. 3) The impact range of SMMs as a function of ferromagnetic electrode type elucidated by the spatial distribution of the magnetic moment of the ferromagnetic electrodes. Our MC study explains experimentally observed effects due to variation of the type of ferromagnetic electrodes².
1.P. Tyagi, Journal of Materials Chemistry 21 (13), 4733-4742 (2011)
2.P. Tyagi, C. Baker and C. D’Angelo, Nanotechnology 26 (30), 305602 (2015)