UC Riverside

This dissertation concentrates on the characteristics of graphene, a single layer of graphite, defined as two-dimensional material for carbon based magnetism and electronics. Carbon materials, which are demonstrated by diamond and graphite, have always been of great interest for their unique properties. Moreover, in the last two decades, there have been three revolutionary milestones in the development of carbon materials, which were related to the discovery of fullerenes, carbon nanotubes, and graphene, respectively. Such research evolution led to the realization of the feasibility to tailor magnetic and electronic properties of graphitic sheets.

Magnetism of carbon materials is of particular interest because of its new and relatively unexplored origins. The technological potential of the new materials is enormous as they promise to become the first room-temperature ferromagnetic semiconductors - the Holy Grail of the world of electronics. Not to mention that the existence of the new materials is vital for the emerging field of spintronics. Researchers believe that new carbon-based magnetic materials could greatly extend the limits of current technologies relying on magnetic and semiconducting properties. In this work, the magnetic properties of pristine graphene and chemically modified graphene were mainly investigated. The chemical functionalization with nitrophenyl (NP) groups was performed by covalent attachment of aryl groups to the basal plane of carbon atoms. The functionalized samples were found to be in mixed state of ferromagnetic and antiferromagnetic states with spins aligned in the main plane at room temperature.

Based on these findings, this work attempted to identify the origins of the intrinsic magnetism and potential ways to tailor magnetism in graphene. Such technology has great potential to pave a way to the next-generation technologies containing high-speed and high-density nonvolatile memory as well as the production of reconfigurable logic devices, integrated magneto-optical devices, quantum information devices, and many devices.