TY - JOUR
T1 - Effects of air exposure on hard and soft X-ray photoemission spectra of ultrananocrystalline diamond/amorphous carbon composite films
AU - Egiza, Mohamed
AU - Naragino, Hiroshi
AU - Tominaga, Aki
AU - Hanada, Kenji
AU - Kamitani, Kazutaka
AU - Sugiyama, Takeharu
AU - Ikenaga, Eiji
AU - Murasawa, Koki
AU - Gonda, Hidenobu
AU - Sakurai, Masatoshi
AU - Yoshitake, Tsuyoshi
N1 - Publisher Copyright:
© 2019 by the authors.
PY - 2018
Y1 - 2018
N2 - Hard X-ray photoemission spectroscopy (HAXPES) was employed for the structural evaluation of ultrananocrystalline diamond/amorphous carbon (UNCD/a-C) composite films deposited on cemented carbide substrates, at substrate temperatures up to 550 °C by coaxial arc plasma deposition. The results were compared with those of soft X-ray photoemission spectroscopy (SXPES). Since nanocrystalline diamond grains are easily destroyed by argon ion bombardment, the structural evaluation of UNCD/a-C films, without the argon ion bombardment, is preferable for precise evaluation. For samples that were preserved in a vacuum box after film preparation, the sp3 fraction estimated from HAXPES is in good agreement with that of SXPES. The substrate temperature dependencies also exhibited good correspondence with that of hardness and Young's modulus of the films. On the other hand, the sp3 fraction estimated from SXPES for samples that were not preserved in the vacuum box had an apparent deviation from those of HAXPES. Since it is possible for HAXPES to precisely estimate the sp3 fraction without the ion bombardment treatment, HAXPES is a feasible method for UNCD/a-C films, comprising nanocrystalline diamond grains.
AB - Hard X-ray photoemission spectroscopy (HAXPES) was employed for the structural evaluation of ultrananocrystalline diamond/amorphous carbon (UNCD/a-C) composite films deposited on cemented carbide substrates, at substrate temperatures up to 550 °C by coaxial arc plasma deposition. The results were compared with those of soft X-ray photoemission spectroscopy (SXPES). Since nanocrystalline diamond grains are easily destroyed by argon ion bombardment, the structural evaluation of UNCD/a-C films, without the argon ion bombardment, is preferable for precise evaluation. For samples that were preserved in a vacuum box after film preparation, the sp3 fraction estimated from HAXPES is in good agreement with that of SXPES. The substrate temperature dependencies also exhibited good correspondence with that of hardness and Young's modulus of the films. On the other hand, the sp3 fraction estimated from SXPES for samples that were not preserved in the vacuum box had an apparent deviation from those of HAXPES. Since it is possible for HAXPES to precisely estimate the sp3 fraction without the ion bombardment treatment, HAXPES is a feasible method for UNCD/a-C films, comprising nanocrystalline diamond grains.
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U2 - 10.3390/COATINGS8100359
DO - 10.3390/COATINGS8100359
M3 - Article
AN - SCOPUS:85065056480
SN - 2079-6412
VL - 8
JO - Coatings
JF - Coatings
IS - 10
M1 - 359
ER -