Molecule Induced Strong Coupling between Ferromagnetic Electrodes of a Molecular Spintronics Device

Abstract

Utilizing molecules for tailoring the exchange coupling strength between ferromagnetic electrodes can produce novel metamaterials and molecular spintronics devices (MSD). A practical way to produce such MSD is to connect the molecular channels to the electrodes of a magnetic tunnel junction (MTJ). This paper discusses the dramatic changes in the properties of MTJ testbed of a MSD due to molecular device elements with a net spin state. When organometallic molecular complexes (OMCs) were bridged across the insulator along the exposed side edges, a MTJ testbed exhibited entirely different magnetic response in magnetization, ferromagnetic resonance and magnetic force microscopy studies. OMCs only affected the ferromagnetic material when it was serving as the electrode of a tunnel junction. Molecule produced the strongest effect on the MTJ with electrodes of dissimilar magnetic hardness. This study encourages the validation of this work and exploration of similar observations with the other combinations MTJs and molecules, like single molecular magnet, porphyrin, and molecular clusters.