Interaction between magnetic molecules and two ferromagnetic electrodes of a magnetic tunnel junction (MTJ)

Abstract

This paper focuses on Monte Carlo Simulations (MCS) to investigate the effects of variations in molecular exchange coupling strengths and nature between the magnetic molecules and ferromagnetic electrodes in cross-junction-shaped magnetic tunnel junction (MTJ) based molecular spintronics devices (MTJMSD). To encompass a wide range of futuristic molecular spintronics devices, we systematically studied the effect of a magnetic molecule analog coupling with two ferromagnetic electrodes. We studied three cases when molecules established: (i) Ferromagnetic couplings with two ferromagnetic electrodes, (ii) Antiferromagnetic couplings with two electrodes, and (iii) Ferromagnetic coupling with one electrode and antiferromagnetic coupling with another electrode. We varied the strength and nature of exchange coupling to study the temporal and spatial propagation of molecular coupling impact on two ferromagnetic electrodes. Our results showed that in the cases when molecular coupling strength was ~ 10% of the ferromagnetic electrode’s Curie temperature, then 16 molecular analogs could influence the magnetic properties of 2,500 atoms above room temperature. This theoretical study is directly in agreement with the experimental observation of ~ 10,000 Single Molecular Magnet (SMM) channels controlling the magnetic and transport properties of microscopic cross-junction-shaped MTJ testbed above room temperature.