Mechanism of Thin Layers Graphite Formation by 13C Implantation and Annealing

Applied Sciences

Gaelle Gutierrez¹  François Le Normand²  Fitsum Aweke¹  Dominique Muller¹  Claude Speisser¹ 

[1] ICube-Laboratoire des Sciences de l’Ingénieur, de l’Informatique et de l’Imagerie, Université de Strasbourg-CNRS, 23, rue du Loess, Strasbourg Cedex 67037, France;

关键词: carbon;    graphene;    thin layers graphite;    nickel;    nuclear reaction analysis;    Raman spectroscopy;    Raman imaging;    nucleation;    ¹³C isotope;   

DOI  :  10.3390/app4020180

来源: mdpi

【 摘 要 】

The mechanism of thin layers graphite (TLG) synthesis on a polycrystalline nickel film deposited on SiO₂ (300 nm thick)/Si(100) has been investigated by ¹³C implantation of four equivalent graphene monolayers and annealing at moderate temperatures (450–600 °C). During this process, the implanted ¹³C segregates to the surface. Nuclear Reaction Analyses (NRA) are used for the first time in the topic of graphene synthesis to separate the isotopes and to determine the ¹²C and ¹³C concentrations at each step. Indeed, a significant part of carbon in the TLG also comes from residual ¹²C carbon absorbed into the metallic matrix. Raman spectroscopy and imaging are used to determine the main location of each carbon isotope in the TLG. The Raman mappings especially emphasize the role of ¹²C previously present at the surface that first diffuses along grain boundaries. They play the role of nucleation precursors. Around them the implanted ¹³C or a mixture of bulk ¹²C–¹³C aggregate and further precipitate into graphene-like fragments. Graphenization is effective at around 600 °C. These results point out the importance of controlling carbon incorporation, as well as the importance of preparing a uniform nickel surface, in order to avoid heterogeneous nucleation.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.