Near-Edge X-Ray Absorption Fine Structure of Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Films Prepared by Pulsed Laser Deposition

• Main Authors: Shinya Ohmagari, Tsuyoshi Yoshitake, Akira Nagano, Sausan AL-Riyami, Ryota Ohtani, Hiroyuki Setoyama, Eiichi Kobayashi, Kunihito Nagayama
• Format: Article
• Language: English
• Published: Hindawi Limited 2009-01-01
• Series: Journal of Nanomaterials
• Online Access: http://dx.doi.org/10.1155/2009/876561

The atomic bonding configuration of ultrananocrystalline diamond (UNCD)/hydrogenated amorphous carbon (a-C:H) films prepared by pulsed laser ablation of graphite in a hydrogen atmosphere was examined by near-edge X-ray absorption fine structure spectroscopy. The measured spectra were decomposed with simple component spectra, and they were analyzed in detail. As compared to the a-C:H films deposited at room substrate-temperature, the UNCD/a-C:H and nonhydrogenated amorphous carbon (a-C) films deposited at a substrate-temperature of 550∘C exhibited enhanced 𝜋∗ and 𝜎∗C≡C peaks. At the elevated substrate-temperature, the 𝜋∗ and 𝜎∗C≡C bonds formation is enhanced while the 𝜎∗C–H and 𝜎∗C–C bonds formation is suppressed. The UNCD/a-C:H film showed a larger 𝜎∗C–C peak than the a-C film deposited at the same elevated substrate-temperature in vacuum. We believe that the intense 𝜎∗C–C peak is evidently responsible for UNCD crystallites existence in the film.