Magnetic transport properties of magnetic porphyrins connected to graphene nanoribbon electrodes

Abstract

Graphene and graphene nanoribbons (GNRs) are ideal systems for contacting functional molecules due to their extraordinary electron mobility and structural stability under high currents. In our previous work, we have shown the construction and magnetic characterization of a fully functional hybrid molecular system composed of a single magnetic porphyrin molecule covalently bonded to GNRs on a gold substrate. To better exploit the functionality of the devices, the magnetic transport measurement of the device is needed. Here in this work, by modifying the molecular precursors, the magnetic porphyrins were fused into two GRNs electrodes in one-dimensional manner. The STM tip was used to contact one GNRs electrode and lift the functional hybrid devices from the surface to form transport junctions. By means of inelastic tunneling spectroscopy, we identify the presence of the spin states of the magnetic porphyrin in the transport junctions although the GNRs electrodes are semiconductor. And we find that the magnetic anisotropy energy does not depends on length of the GNRs electrodes, but it is related to the d orbital of the magnetic porphyrin due to the e-e interactions.