The influence of helium ion irradiation on amorphous hydrocarbon films

• Published in: Journal of nuclear materials Vol. 435; no. 1-3; pp. 214 - 221
• Main Authors: Fan, Hongyu, Sun, Li, Yang, Deming, Niu, Jinhai, Guo, Liping, Yang, Qi, Bi, Zhenhua, Liu, Dongping
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.04.2013; Elsevier
• Subjects: Applied sciences; Atomic force microscopy; Clusters; Controled nuclear fusion plants; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fission nuclear power plants; Fuels; Hydrocarbons; Installations for energy generation and conversion: thermal and electrical energy; Ion irradiation; Irradiation; Networks; Nuclear fuels; Scratching; Three dimensional; Mechanical properties; Helium ion; Ion irradiation; Chemical properties; Roughness; Nuclear reactor
• ISSN: 0022-3115; 1873-4820
• DOI: 10.1016/j.jnucmat.2012.12.048

Amorphous hydrocarbon films were irradiated with 60–140keV He ions at the dose ranging from 1.0×1015 to 1.0×1017ions/cm2. The films about 1.4μm thick were deposited on Si substrates and irradiated at room temperature. The surface and mechanical properties of as-deposited and He ion irradiated hydrocarbon films were analyzed by using atomic force microscopy (AFM), AFM-based nanoindentation and scratching tests. Their chemical compositions and structural properties were evaluated by FTIR and Raman measurements. Analysis showed that the He ion irradiation led to a decrease in their surface roughness and an increase in the nanohardness and scratching resistance. FTIR measurements indicated that the content of bonded H atoms in hydrocarbon samples was greatly decreased due to the He ion irradiation, and a dense and covalent three-dimensional network was formed in films. The Raman data confirmed the microstructural evolution of samples into a dense metastable structure containing a large fraction of sp2 C clusters.