Low-temperature investigation of paramagnetic centres in tetrahedral amorphous carbon deposited by S-bend FCVA
نویسندگان
چکیده
The electron-spin-resonance (ESR) features of tetrahedral amorphous carbon (ta-C) samples deposited by S-bend filtered cathodic vacuum arc (FCVA) are investigated in a wide temperature range (4.3–295 K) before and after postdeposition annealing at 500 C. Special attention is given to the temperature dependence of the linewidths. While the sp content does not change with annealing, the temperature trend of the linewidth becomes much smoother for postdeposition annealed samples. The results are discussed in terms of different possible mechanisms of motional linenarrowing and line-narrowing due to hopping motion. 2002 Elsevier Science B.V. All rights reserved. PACS: 81.05.uw; 76.30.-v; 66.35.+a
منابع مشابه
MAGNETISATION AND ELECTRON SPIN RESONANCE STUDIES OF TETRAHEDRAL AMORPHOUS CARBON
The magnetisation and electron spin resonance (ESR) spectrum of two specimens of tetrahedral amorphous carbon (ta-C), deposited from a filtered cathodic arc, were measured over a wide temperature range. The magnetisation was found to consist of superparamagnetic, paramagnetic and diamagnetic contributions. The superparamagnetic contribution resembled that recently found in carbon prepared from ...
متن کاملElectrical behaviour of metal / tetrahedral amorphous carbon / metal structure
Silicon and GaAs based devices are limited in their high-temperature applications as these materials lack high sensitivity to the temperature range above 200°C due to their small band gaps. Therefore, exploration of new materials with a high-temperature performance is necessary. Diamond-like carbon as a semiconducting material may be one of the promising candidates due to its many properties cl...
متن کاملEffect of graphitic inclusions on the optical gap of tetrahedral amorphous carbon films
High sp fraction tetrahedral amorphous carbon (ta-C) films can be prepared using the filtered cathodic vacuum arc ~FCVA!. A by-product of the deposition process are small micrometer sized graphitic particles which are also incorporated into the film. The particle coverage of FCVA films is typically ,5%, and thus the effect of these graphite inclusions have been largely ignored in earlier optica...
متن کاملCyclic Voltammetric Behavior of Nitrogen-Doped Tetrahedral Amorphous Carbon Films Deposited by Filtered Cathodic Vacuum Arc
Nitrogen-doped tetrahedral amorphous carbon (ta-C :N) films were deposited by filtered cathodic vacuum arc (FCVA) technique using nitrogen as a background gas. The structure of the ta-C :N films was studied with X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy in terms of nitrogen flow rate used during the film deposition. Potential windows of the films measured in deaerated and un...
متن کاملUltra-thin tetrahedral amorphous carbon films with strong adhesion, as measured by nanoscratch testing
Amorphous carbon can form hard and dense films, which find applications for tooling components, magnetic recording, etc. The challenge is to prepare hard layers that have good adhesion to the substrate. Moreover, mechanical characterisation of sub20 nm layer is still difficult and semi-quantitative. The paper is addressing these issues. We prepared 10-nm and 50-nm thick tetrahedral amorphous ca...
متن کامل