Magnetic tunnel junction based molecular spintronics devices exhibiting current suppression at room temperature

Molecular bridges covalently bonded to two ferromagnetic electrodes can transform ferromagnetic materials and produce intriguing spin transport characteristics. Previously, we theoretically and experimentally studied the impact of paramagnetic molecules on the magnetic properties of the magnetic tunnel junctions (Tyagi et al. Nanotechnology, Vol.26, p.305602, 2015). In this follow up paper we have investigated the impact of previously demonstrated molecule induced strong coupling on the spin transport. To study molecular coupling effect experimentally we attached paramagnetic molecules between two ferromagnetic electrodes of a magnetic tunnel junction along the exposed side edges. The strong molecule coupling between two ferromagnetic electrodes caused the drastic changes in transport properties of the magnetic tunnel junction testbed. Molecular transport channels along the tunnel junction edges decreased the tunneling current as compared to the leakage current of the bare tunnel junction at room temperature. The current magnitude on the paramagnetic molecule treated magnetic tunnel junction tended to settle in the suppressed state at room temperature. [Display omitted] •Covalently bonded molecules created experimentally-observed strong antiferromagnetic coupling between ferromagnets of MTJ.•Upto ~ 7 orders of current reduction below leakage current of MTJ occurred on MTJMSD due to molecular bridges at RT.•In the transient state MTJ+molecules (aka MTJMSD) showed irreproducible magnetoresistance change by >1000 folds at RT.•In the transient state forcing current through MTJMSD showed irreproducible resistance change by >1000 folds at RT.•MTJMSD approach may allow mass production of molecular quantum properties based future computing and memory devices.