TY - JOUR
T1 - Near- And far-field Raman spectroscopic studies of nanodiamond composite films deposited by coaxial arc plasma
AU - Ali, M. Ali
AU - Deckert-Gaudig, Tanja
AU - Egiza, Mohamed
AU - Deckert, Volker
AU - Yoshitake, Tsuyoshi
N1 - Funding Information:
This research was partially financially supported by the Osawa Scientific Studies Grants Foundation, Advanced Machining Technology & Development Association, JST A-STEP Stage II (No. AS2915051S), and JSPS KAKENHI Grant No. JP19H02436. Ali M. Ali is grateful for the financial assistance provided by the Kyushu University Advanced Graduate Program in Global Strategy. V. Deckert was partly supported by the Deutsche Forschungs Gemeinschaft (DFG) via the Collaborative Research center SFB 1278 (Polytarget—Project B04).
Publisher Copyright:
© 2020 Author(s).
PY - 2020/1/27
Y1 - 2020/1/27
N2 - Raman spectroscopic studies on nanodiamond composite (NDC) films, comprising nano-sized diamond grains and an amorphous carbon (a-C) matrix, deposited by coaxial arc plasma deposition are challenging because the scattering of the nano-sized diamond grains competes with the strong signal of the a-C matrix. To unravel the nanocomposite structure of NDC films, both far- and near-field Raman spectroscopy were employed. Based on the comparison of visible and ultraviolet far-field Raman data, component spectra based on either nanodiamond or a-C were estimated by a peak-decomposition procedure based on band fitting. Near-field optical resolution achieved via tip-enhanced Raman spectroscopy reveals sharper peaks of both the nanodiamond and the amorphous carbon than the far-field spectra. Consequently, the peak-decomposition procedure is not required, which evidently indicates the effective detection of nanodiamond grains embedded in a-C matrices and is a direct result of the high spatial resolution that limits the number of probed grains. The size of the nanocrystals could additionally be estimated from the profile and position of a diamond peak. This work demonstrates that tip-enhanced Raman spectroscopy is a powerful nondestructive method for nanodiamond composite films, which allows direct access to parameters hitherto only available via average data.
AB - Raman spectroscopic studies on nanodiamond composite (NDC) films, comprising nano-sized diamond grains and an amorphous carbon (a-C) matrix, deposited by coaxial arc plasma deposition are challenging because the scattering of the nano-sized diamond grains competes with the strong signal of the a-C matrix. To unravel the nanocomposite structure of NDC films, both far- and near-field Raman spectroscopy were employed. Based on the comparison of visible and ultraviolet far-field Raman data, component spectra based on either nanodiamond or a-C were estimated by a peak-decomposition procedure based on band fitting. Near-field optical resolution achieved via tip-enhanced Raman spectroscopy reveals sharper peaks of both the nanodiamond and the amorphous carbon than the far-field spectra. Consequently, the peak-decomposition procedure is not required, which evidently indicates the effective detection of nanodiamond grains embedded in a-C matrices and is a direct result of the high spatial resolution that limits the number of probed grains. The size of the nanocrystals could additionally be estimated from the profile and position of a diamond peak. This work demonstrates that tip-enhanced Raman spectroscopy is a powerful nondestructive method for nanodiamond composite films, which allows direct access to parameters hitherto only available via average data.
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U2 - 10.1063/1.5142198
DO - 10.1063/1.5142198
M3 - Article
AN - SCOPUS:85078866777
SN - 0003-6951
VL - 116
JO - Applied Physics Letters
JF - Applied Physics Letters
IS - 4
M1 - 041601
ER -