High energy-resolution EELS study of the electronic structure of nanotubes

Results obtained are as follows.(1)The special resolution of a high energy-resolution EELS microscope was greatly impoved from 180 nm to 35 nm in diameter by using an aperture of 1µm in diameter.(2)EELS spectra were obtained from a tip and a body areas of one carbon nanotube。It was revealed that the density of stated of theπ*-band is different from that of graphite.(3)EELS spectra were obtained from single BN nanotubes.It was found that the bandgap energies of BN nanotubes were smaller than that of hexagonal BN by an amount of 0.7 eV。Intensity distributions of the plasmon peak were well explained not by a volume loss-function but by a surface loss-function.(4)EELS spectra of dimer-，one-dimensional-and two-dimensional-polymerized C I D260文件D2 were obtained from single crystalline as for the first time.The bandgap energies of the materials were smaller than that of monomer C ei D260锡D2 single crystal by an amount of 0.1-0.3 eV。Intensity distributions ofπtoπ*interband transitions was broader than that of monomer C I D 260个D 2.Those results were explained by a deformation of C I D260锡D2 cluster due to the polymerization.

Results obtained are as follows.(1) The special resolution of a high energy-resolution EELS microscope was greatly impoved from 180nm to 35nm in diameter by using an aperture of 1μm in diameter.(2) EELS spectra were obtained from a tip and a body areas of one carbon nanotube. It was revealed that the density of stated of the π*-band is different from that of graphite.(3) EELS spectra were obtained from single BN nanotubes. It was found that the bandgap energies of BN nanotubes were smaller than that of hexagonal BN by an amount of 0.7eV. Intensity distributions of the plasmon peak were well explained not by a volume loss-function but by a surface loss-function.(4) EELS spectra of dimer-, one-dimensional- and two-dimensional-polymerized CィイD260ィエD2 were obtained from single crystalline areas for the first time. The bandgap energies of the materials were smaller than that of monomer CィイD260ィエD2 single crystal by an amount of 0.1-0.3eV. Intensity distributions of π to π* interband transitions was broader than that of monomer CィイD260ィエD2. Those results were explained by a deformation of CィイD260ィエD2 cluster due to the polymerization.