Graphene better then Diamond Graphene and diamond is made of pure carbon
Properties of the nanodiamond Nanodiamond: • synthesized by the detonation; • narrow size distribution; • diamond-like; • Widely used in the industry Nanodiamond: Structure: sp3 carbon bond has π electron networks; unconventional magnetism around thegraphene/diamond interface; Nanographine: Non bonding π electron state ==> rise of unconventional nanomagnetism;
Diamond-to-graphite Diamond-to-graphite conversion in nanodiamond and electronic properties of nanodiamond-derived carbon system. Heat-treatment-induced (HTT-Heat treatment temperature) conversion of nanodiamond to nanographite is investigated. • Graphitization starts at 900C; • proceeds inward in the particle; • completed around 1600C, were a nanodiamond particle converted to a single nanographene sheet; Analysing: • Structure; electronic aspects; X-Ray diffraction; high resolution transmission electron micro-scope (HRTEM), scanning electron microscope (SEM),Raman scattering, scanning tunneling microscope (STM), atomic force microscope (AFM), magnetic susceptibility and ESR. E
Structural parameters • Shape of nanographine particle; • Particle forms Polyhedron of size ca 7nm and a hollow inside; • Regularity of graphitic structure; • Turbostatic nature of the graphene sheets;
Electronic properties The electronic properties described analysing magnetic properties. • Extended π – electron system; • π – electron spins coupled; • Accelerated spin-lattice relaxation process;
Electronic properties cont. • Minimal defects; • Disordness of graphite; • Stiffennes of the graphitic lattice; • Partly vacant π-band bonding - holes; • Reduction of the orbital susceptibility
Formation of isolated single nanographene layer • Electrophoretic deposition • Successive heat treatment of isolated nanodiamond particles is expected to produce isolated nanographite particles on a substrate. • obtained particle can be assigned to a single nanographene sheet laying flat on the HOPG (highly oriented pyrolytic graphite) substrate. • Nanodiamond particles when simply heated at 1600C yields the polyhedral nanographite particles • First observation of a single nanographene sheet.
Images of the nanodiamond and nanographie particles using electrophoretic deposition
Graphene future in today's industry Paper-like graphene: • Flexible; • tougher than diamond; • lighter then most metals; • different electrical properties. Graphene can be used: • touch screens; • solar cells; • energy-storage devices; • cell phones; • high-sped computer chips. Graphene may be the ticket to major technological breakthrough; “It is the thinnest known material in the universe, and the strongest ever measured,” wrote University of Manchester physicist Andre Geim in Science.