Expectedly, such low-energy interactions of cluster target can lead to little cascade collisions. Raman spectra indicate that there is an amorphous carbon film on the sample due to sp2 hybridized carbon atoms forming π-bond to enhance Raman scattering cross section, which is performing drastic peak intensities

at about 1,560 cm−1. In conjunction with the surface morphology of AFM image, the amorphous layer exhibits continuous distributions on the whole substrate except some possible island-like contaminations in the form of white spots. Certainly, these columnar protuberances may be some larger grain accumulations induced by higher energetic ions landing on the edge than that in the center of the sample, depending on the strength distribution of decelerated field. The value of root mean square roughness (RMS) is about 5.10 nm for thin film, which indicates a great promise of preparing ultra-thin Caspase inhibitor film under much lower energy ion implantation. Figure 2 Raman spectra and AFM image of the sample by C 4 cluster ion implantation. Few-layer graphene synthesis It is an essential purpose that we designed this low-energy cluster chamber for graphene preparation. In the process of exploring some effective methods, after depositing carbon films with

the scale of several nanometers on the silicon, we selected suitable substrates to succeed in achieving few-layer graphene. Uninstalling the decelerated field, we selected small carbon cluster ions to inject to the substrate below 30 keV. The substrate Ni/SiO2/Si with about 300 nm Ni film deposited Ni atoms onto silica by e-beam AP26113 nmr evaporating. The thickness of Ni film has influence

on carbon segregation from inside up to the surface, so it is significant to evaluate the thickness of the substrate, and RBS spectra of the sample was carried out, as shown in Figure 3. Incident 2.86 MeV Li2+ which was produced by the double 1.7 MV tandem accelerator was collimated to the target with ion current of 5 nA and the round beam spot of 1.5 mm. The backscattered ions were detected by passivated implanted planar silicon (PIPS) detector with the resolution of 14 keV for α particle at 165°. The abscissa Rebamipide of spectra stands for channel numbers of multi-channel analyzer (MCA), which is proportional to the energy of scattered ions. A broad peak indicates that the surface edge of Ni is about channel 269 and the back edge is about channel 195. The channel difference of both edges is corresponding to the energy loss of projectile Li ions in Ni in correlation with the thickness of thin film. A straightforward route is simulating the trajectories of incident ions in matter. The red curve of this graph is simulation result from SIMNRA6.05 code, which is in coincidence with experimental data absolutely. The simulated results reveal that the areal density of Ni film is 2.1 × 1018 atoms/cm2, and a corresponding thickness is 227.