| We have studied the static and dynamic properties of small transition metal clusters interacting with non-metallic carbon based systems. The static properties are computed using first Principles Density Functional Theory (DFT) while the electron transport is calculated using Landauer-Buttiker formalism.; The ground state properties of small iron clusters deposited on a coronene substrate are studied using DFT and generalized gradient corrected approximation for exchange and correlation functional. We have shown that both in neutral and cationic Fen-coronene complexes, the iron atom prefers to bind the electron rich regime of the coronene. While the dissociation channels do agree with experiment qualitatively, there are significant quantitative differences between theory and experiment, which are explained using multi-photon processes. The spin of supported iron clusters, though quenched from their gas phase values, is still higher compared to that of bulk iron. This suggests that polarized electrons can be injected to carbon based molecular systems when interfaced with magnetic cluster.; For the system involving molecular wire, we have demonstrated that the ground states have anti parallel spin configurations when sandwiched between Ni (or Mn) cluster layers. This is worth mentioning here that the anti parallel configuration is extremely difficult proposition from experimental point of view in such nano scale systems. The spin polarized transport computed using Landauer-Buttiker formalism in the molecular systems reveals that this can be used as spin valve due to large difference in resistance between parallel and anti-parallel configurations.; The roles of spin-polarized electrons in one-dimensional atomic wire are studied both for its electronic structure properties and transport. The ground states in these atomic systems are found to have anti parallel configurations, which are of great interest from experimental point of view. The super exchange, which stabilized the anti parallel configurations of even carbon atom chains, has less contribution when the chain length increases beyond a characteristic length. More interestingly, the magneto conductance shows oscillatory behavior with chain length, which could be used in magneto-electronics. |
