Research Projects

Paramagnetic molecules can be coupled with the spin of ferromagnetic electrodes, such as permalloy (Ni80Fe20), whose magnetization can be tuned by a magnetic field.6 The ferromagnetic electrode offers asymmetric densities of electronic states (DOS) near the Fermi level (EF) as shown in Scheme 1. An external static magnetic field can tune the spin density between UP and DOWN. This setup enables the investigation of the interaction of localized magnetic moments within the molecular thin films with spin-selective electrons conduction.7 In the presence of a magnetic field, paramagnetic molecules experience energy state redistribution due to Zeeman splitting (Scheme 2). Unpaired electrons can contribute to spin filtering under these conditions.8 Here, we aim to fabricate cross-bar two-terminal molecular junctions (MJs) incorporating paramagnetic metal complexes such as Cu(tpy)2 oligomer films (2-20 nm thickness) on permalloy electrodes. Oligomeric molecular films will be prepared on ferromagnetic permalloy (Ni80Fe20) electrodes via the electrochemical grafting method via aryl diazonium salts reduction. By systematically varying the electrochemical potential window, thickness of the molecular layers can be varied, thus, to see interaction between adjacent paramagnetic centre that may couple ferromagnetically or antiferromagnetically. We seek to gain deeper insights into magnetic field-driven current conduction mechanisms in paramagnetic oligomeric molecular junctions.