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Ultrathin epitaxial graphite was grown on single-crystal silicon carbide by vacuum graphitization. The material can be patterned using standard nanolithography methods. The transport properties, which are closely related to those of carbon nanotubes, are dominated by the single epitaxial graphene layer at the silicon carbide interface and reveal the Dirac(More)
Graphene nanoribbons will be essential components in future graphene nanoelectronics. However, in typical nanoribbons produced from lithographically patterned exfoliated graphene, the charge carriers travel only about ten nanometres between scattering events, resulting in minimum sheet resistances of about one kilohm per square. Here we show that(More)
Urbanization is arguably the most dramatic form of highly irreversible land transformation. While urbanization is a worldwide phenomenon, it is exceptionally dynamic in India, where unprecedented urban growth rates have occurred over the last 30 years. In this uncontrolled explosive situation city planning lacks of data and information to measure, monitor,(More)
The reduced form of graphene oxide (GO) is an attractive alternative to graphene for producing large-scale flexible conductors and for creating devices that require an electronic gap. We report on a means to tune the topographical and electrical properties of reduced GO (rGO) with nanoscopic resolution by local thermal reduction of GO with a heated atomic(More)
Recently discovered multilayered epitaxial graphene (MEG) consists of un-charged and electronically decoupled graphene layers. Its properties are well described by those of a single graphene sheet. The Dirac particle properties in MEG are more compelling than in exfoliated graphene: the Fermi level is found to be within a few meV of the well-defined Dirac(More)
We present a structural analysis of the multi-layer graphene-4HSiC(000 ¯ 1) system using Surface X-Ray Reflectivity. We show for the first time that graphene films grown on the C-terminated (000 ¯ 1) surface have a graphene-substrate bond length that is very short (1.62Å). The measured distance rules out a weak Van der Waals interaction to the substrate and(More)
Electronic carriers in graphene show a high carrier mobility at room temperature. Thus, this system is widely viewed as a potential future charge-based high-speed electronic material to complement-or replace-silicon. At the same time, the spin properties of graphene have suggested improved capability for spin-based electronics or spintronics and spin-based(More)
The maximum oscillation frequency (fmax) quantifies the practical upper bound for useful circuit operation. We report here an fmax of 70 GHz in transistors using epitaxial graphene grown on the C-face of SiC. This is a significant improvement over Si-face epitaxial graphene used in the prior high-frequency transistor studies, exemplifying the superior(More)
BACKGROUND Mediastinal involvement (MI) in Langerhans cell histiocytosis (LCH) has been rarely reported. Here, we describe the clinical, radiological, and biological presentation, and the outcome of childhood LCH with MI. METHOD From the French LCH register, which includes 1,423 patients aged less than 18 years, we retrieved the medical charts of patients(More)