Cu atoms deposited on a zero layer graphene grown on a SiC(0001) substrate, intercalate between the zero layer graphene and the SiC substrate after the thermal annealing above 600 °C, forming a Cu-intercalated single layer graphene. On the Cu-intercalated single layer graphene, a graphene lattice with superstructure due to moiré pattern is observed by scanning tunneling microscopy, and specific linear dispersion at the K¯ point as well as a characteristic peak in a C1s core level spectrum, which is originated from a free-standing graphene, is confirmed by photoemission spectroscopy. The Cu-intercalated single layer graphene is found to be n-doped.

Articles you may be interested inScanning tunneling microscopy observations of hafnium carbide thin films as a field emission material J. Vac. Sci. Technol. B 23, 741 (2005); 10.1116/1.1849192 Current image tunneling spectroscopy of boron-doped nanodiamonds J. Appl. Phys. 97, 044312 (2005); 10.1063/1.1834722 Development of an in situ ultra-high-vacuum scanning tunneling microscope in the beamline of the 15 MV tandem accelerator for studies of surface modification by a swift heavy ion beam Rev. Sci. Instrum. 72, 3884 (2001);

The solubilities of undecanolide (UDL) and pentadecanolactone (PDL) in supercritical carbon dioxide (SC-CO 2 ) were measured at 308.2 K and 318.2 K over the pressure range from 9.1 MPa to 25.3 MPa by a flow type apparatus. The solubilities were determined from the mass of solute trapped by decompression and the volume of CO 2 . Solubility data were correlated by a solution model based on the regular solution concept.

Pd-intercalated graphene grown on a SiC(0001) substrate was investigated using STM, angle-resolved photoemission spectroscopy, and XPS. Pd atoms deposited at room temperature on a zero layer graphene grown on a SiC(0001) substrate were intercalated between the zero layer graphene and the SiC substrate after the thermal annealing above 700 °C, forming a Pd-intercalated single layer graphene. No charge transfer occurred between the intercalated Pd layer and the graphene, which resulted in the formation of the electrically neutral graphene. The Pd-intercalated graphene remained electrically neutral throughout the annealing temperature range between 700 and 1100 °C. The charge transfer, however, occurred between the intercalated Pd layer and the SiC substrate, which caused a band bending confirmed in the core level spectra measured by XPS.

Scanning tunnelling microscopy (STM) and current imaging tunnelling current spectroscopy (CITS) methods were performed on polycrystalline diamond films grown on silicon substrates grown by microwave plasma-enhanced chemical vapour deposition. Large tunnelling currents were observed at some grain boundaries and crystal surfaces with secondary grains. Following atomic force microscopy (AFM) measurements, we performed scanning probe contact current (SPCC) measurements to investigate the spatial variation of electrical resistance on the surface by using an AFM cantilever in contact mode. The conducting grain boundaries and facets were observed on both boron-doped and undoped samples. For microscale characterization of the field emission properties, we performed scanning probe field emission current (SPFEC) measurements. From the results of STM/CITS, AFM/SPCC and SPFEC, it is concluded that the specific grain boundaries and facets on polycrystalline diamonds work as initial points of electron emission and cause high field emission current through a conducting pass formed in the bulk.