How crucial is the role of magnetic centres in tuning magneto-resistive features of one-dimensional transition metal-based magnetic nanostructures?

Abstract

Magnetic tunnel junctions are created by alternating relative spin orientation of ferromagnetic electrodes or spin orientation of magnetic centres in the channel/ insulating tunnel barrier separating two ferromagnetic electrodes. The performance of the resulting device is estimated through tunnelling magnetoresistance (TMR), known as a spin valve. Herein, we present an extensive report on the influence of dual action of spin orientation of atomic magnetic centres and ferromagnetic electrodes, as well as the length of the insulating spacer [Mn-C_n-Mn; n = 2 to 8] at eight different relative spin orientations and conclude about the best probable relative orientations and optimum spacer length (n = 7) to achieve very high TMR. A comprehensive mathematical formulation about choosing the perfect combination of relative spin orientation to attain the highest degree of TMR has been proposed. Observed results have been explained through transmission coefficients with a molecular level insight through the study of transmission pathways and molecular projected self-consistent Hamiltonian (MPSH) states. The present study is expected to provide enough evidence to the experimentalists to realise such a device in practice in the near future.