Spectral ellipsometry of a nanodiamond composite

Journal Article · Sat Jul 15 00:00:00 EDT 2006 · Semiconductors

DOI:https://doi.org/10.1134/S1063782606070177· OSTI ID:21088506

Gordeev, S K ^[1]; Garriga, M; Alonso, I A ^[2]; Ivanov-Omskii, V I ^[3]

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1. Central Research Institute for Materials (Russian Federation)
2. CSIC, Institute de Ciencia de Materials de Barcelona (Spain)
3. Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation)

Optical properties of a nanodiamond composite were analyzed by methods of spectral ellipsometry in the range of photon energies 1.4-5 eV, which are characteristic of {pi}-{pi}* transitions in amorphous carbon. The nanocomposite was synthesized by molding nanodiamond powder with subsequent binding of diamond nanoparticles by pyrocarbon formed as a result of the heterogeneous chemical reaction of methane decomposition. The dispersion curves of the imaginary and real parts of the dielectric function were reconstructed. It is shown that the imaginary part of the dielectric function can be represented as the sum of two components generated by the two types of {pi}-{pi}* optical transitions. The maximum contribution of the transitions of the first and second types manifests itself at energies of 2.6 and 5.6 eV, respectively, which correspond to peaks in optical density at 2.9 and 6.11 eV. It was established that the main specific features of the normalized optical density of the nanodiamond composite almost coincide with those for poly(para-phenylenevinylene). It was found that the energy of a {sigma} + {pi} plasmon of the pyrocarbon component of the nanodiamond composite is 24.2 eV. On the basis on this value, the pyrocarbon density matrix was estimated to be 2 g/cm{sup 3}. Within the concepts of optimum filling of an elementary volume by carbon atoms in an amorphous material with such a density, the allotropic composition of the pyrocarbon matrix was restored.

• OSTI ID: 21088506
• Journal Information: Semiconductors, Vol. 40, Issue 7; Other Information: DOI: 10.1134/S1063782606070177; Copyright (c) 2006 Nauka/Interperiodica; Article Copyright (c) 2006 Pleiades Publishing, Inc; Country of input: International Atomic Energy Agency (IAEA); ISSN 1063-7826
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMPOSITE MATERIALS
DECOMPOSITION
DENSITY MATRIX
DIAMONDS
DISPERSIONS
ELLIPSOMETRY
EV RANGE 01-10
METHANE
NANOSTRUCTURES
OPACITY
PARTICLES
PHOTONS
PYROLYTIC CARBON