Effects of Coupling between Single Molecular Magnet (SMM) and Ferromagnetic Electrode on Magnetic Tunnel Junction-Based Molecular Spintronic Devices

Magnetic Tunnel Junction-based Molecular spintronic devices (MTJMSDs) approach allows covalent bonding of Single Molecular Magnet (SMM) between two ferromagnetic electrodes (FMEs) of a MTJ along the exposed sides.This research studies variation of magnetic coupling between the SMM and two FMEs.We conducted Monte Carlo Simulations (MCS) by defining MTJMSD in an Ising model framework.We varied the SMM-FMEs Heisenberg exchange coupling nature and strengths to simulate a wide range of device configurations.In this study we investigated SMM forming (i)FM coupling with two FMEs (ii)anti-FM couplings and (iii) FM coupling with one FME and anti-FM coupling with another one.The SMM-FME coupling variation effect was studied on the magnetic moment, heat capacity, and magnetic susceptibility of the two FME and overall MTJMSD.We also studied the spatial and temporal behavior of MTJMSD as a function of SMM couplings.Our MCS study agrees with the experimental observations of time dependent changes on MTJMSD magnetic and transport properties.Ferromagnetic SMM-FMEs coupling resulted in maximum magnetization while antiparallel couplings led to magnetic moment close to zero.This study provides explanation for the experimentally observed current suppression phenomenon on MTJMSD at room temperature.