High energy-resolution electron energy-loss spectroscopy and soft-x-ray emission spectroscopy studies of amorphous diamond transformed from neutron-irradiated graphite

• Published in: Journal of physics. Conference series 2014-05, Vol.500 (19), p.192013-5
• Main Authors: Sato, Y, Terauchi, M, Niwase, K, Nakamura, K G, Atou, T, Iwata, T
• Format: Article
• Language: English
• Subjects: Buckminsterfullerene; Compressing; Diamonds; Electron density; Electron energy; Electron energy loss spectroscopy; Electrons; Emission analysis; Emission spectroscopy; Energy; Energy gap; Excitation; Excitation spectra; Fullerenes; Graphite; Monochromators; Physics; Spectroscopic analysis; Spectroscopy; Spectrum analysis; Synthesis; Transmission electron microscopy
• ISSN: 1742-6596; 1742-6588; 1742-6596
• DOI: 10.1088/1742-6596/500/19/192013

High energy-resolution electron energy-loss spectroscopy measurements were performed for amorphous diamond (am-DIA), which was synthesized from neutron-irradiated graphite by shock compression, by using a monochromator transmission electron microscope (TEM). Soft-X-ray emission spectroscopy (SXES) measurements were performed by a wavelength-dispersive type spectrometer attached to the monochromator TEM. A volume plasmon peak of am-DIA is observed at 32.5 eV, which is a little smaller than that of crystalline diamond (c-DIA). The smaller plasmon energy of am-DIA indicates a smaller valence electron density of am-DIA than that of c-DIA. From the onset energies of the K-shell excitation and the SXES spectra, the band gap energy of am-DIA is estimated to be 4 eV, which is similar to the value, 3.9 eV, from the valence electron excitation spectrum and reported values, 3.5-4.5 eV, for the am-DIA synthesized from C60 fullerene by shock compression.