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Infrared Reflectance and Dielectric Properties of Pyrolytic Graphite for E ∥ c Polarization
Author(s) -
Venghaus H.
Publication year - 1977
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2220810123
Subject(s) - pyrolytic carbon , dielectric , dielectric function , free carrier , plasma , drude model , polarization (electrochemistry) , atomic physics , materials science , plasma oscillation , reflectivity , graphite , infrared , highly oriented pyrolytic graphite , analytical chemistry (journal) , condensed matter physics , optics , physics , chemistry , optoelectronics , nuclear physics , organic chemistry , chromatography , pyrolysis , composite material
Normal incidence reflectance measurements with E ∥ c polarization are performed on polished surfaces of pyrolytic graphite for 15 meV < ħω < 500 meV and the dielectric function ϵ ∥ (ω) is derived from the data by Kramers‐Kronig analysis. The function ϵ ∥ (ω) is characterized by a background dielectric constant ϵ 0∥ = 5.4 and free carrier contributions below 100 meV. The free carrier contributions can be characterized to a good approximation by Drude‐like behaviour with a plasma energy ħω p∥ ( E ∥ c ) = (101 ± 5) meV, giving rise to a maximum of the energy loss function Im [−1/ϵ ∥ (ω)] at (37 ± 2) meV due to higher lying interband transitions. The plasma frequency determined in the present experiments is in agreement with theoretical estimates of the free carrier plasma frequency.