Magnetic force microscopy revealing long range molecule impact on magnetic tunnel junction based molecular spintronics devices

Magnetic force microscopy (MFM) vividly showed that organometallic molecules, when bridged between two ferromagnetic electrodes along the cross-shaped magnetic tunnel junction edges transformed the magnetic electrodes itself. Molecules impacted a large area of ferromagnetic leads around the junction at room temperature and complement the previous magnetic measurements showing molecule effect on pillar form magnetic tunnel junctions [Ref. P. Tyagi a al. Nanotechnology, 2015, Vol. 26, p 305602]. This molecule induced changes in the magnetic electrodes impacted the transport of the magnetic tunnel junction and stabilized as much as seven orders smaller current at room temperature. We have discussed the current suppression phenomenon in the recent publication [Ref. Tyagi a al. Organic Electronics, 2019, Vol. 64, p 188]; however, we did not provide any direct evidence of molecule impact on ferromagnetic electrodes around molecule junction. Our MFM studies in this paper suggests that molecule effect was observable several mu m away from the molecule-metal junctions. Our study suggests that magnetic tunnel junction based molecular spintronics devices can be a gateway to a vast range of commercially viable and robust futuristic computer devices and highly correlated materials.