Spatial Impact Range of Single Molecule Magnet on Magnetic Tunnel Junction-Based Molecular Spintronic Devices (MTJMSDs)*

Advanced and energy efficient logic and memory devices are needed to produce next generation computers for the adaptation of artificial intelligence like technologies in day-to-day life. Magnetic Tunnel junction based Molecular Spintronic Devices (MTJMSD) can effectively combine ferromagnetic electrode (FME) with magnetic molecules for producing spintronic devices for futuristic computers. This work investigates the effect of FME's length and thickness variation on MTJMSD's molecule-induced correlated magnetic phases and spatial range of molecule impact. Our experimental transport studies show that in a strong FME-molecule coupling regime 10 to 20 nm change in thickness changed MTJMSD conductivity by>1000 fold. Magnetic Force Microscopy (MFM) showed the FME extending beyond the cross-junction area developed multiple room temperature stable magnetic phases. To explore other possible effects, we also conducted Monte Carlo Simulation (MCS) using Heisenberg atomic modeling. Our computational results agree with our experimental observations. According to the MCS study, increasing FME length produced multiple magnetic phases around MTJMSD. On the other hand, increasing FME thickness from 5 to 25 atoms reduced the penetration of molecule coupling impact along the thickness.