Characterization of focused-ion-beam induced defect structures in graphite for the future guided self-assembly of molecules

Abstract

Articles you may be interested inMolecular beam epitaxy growth and characterization of self-assembled MnAs wires on highly oriented pyrolytic graphite J. Vac. Sci. Technol. B 28, C3E6 (2010); 10.1116/1.3357280Erratum: "Characterization of focused-ion-beam induced defect structures in graphite for the future guided selfassembly of molecules" [J.The morphology and periodicity of arrays of single focused-ion-beam induced artificial defects in graphite is probed using scanning tunneling microscopy and modeled through Monte Carlo simulation. While ion dose is kept constant with a fluence of 2.48ϫ 10 15 ions cm −2 , variations in artificial defect morphology are attributed to astigmatism in the beam aperture, to deviation in beam angle, or to distance from beam focal point. Simulation of the collision cascade of the ion in graphite lattice correlates to the artificial defect dimensions of both circular symmetric and elongated asymmetric defects. Periodic arrays of artificial defects exhibit constant periodicities at lower basis dimensions ͑100 nm separation between defects͒, with larger deviations from the periodic structure at higher basis dimensions ͑400 nm separation between defects͒. Well structured periodic arrays of defects are considered for nanostructured patterning of molecules for thin film growth. Local amorphization of graphite due to ion irradiation changes the diffusion field, which can be tailored for the guided self-assembly of molecules.

Floating two-dimensional solid monolayer ofC60on graphite

“…The average distance that C 60 molecules diffuse before joining an island was determined to be about 300-400 nm in an earlier experiment that observed the growth of C 60 islands on graphite with arrays of artificial nucleation sites. 33 In Fig. 4, several lines transect the image.…”

Identification of structural defects in graphitic materials by gas-phase anisotropic etching

“…Alternately, etching techniques could be applied to enlarge the intrinsic defects in graphitic materials to be observable without using atomic resolution imaging techniques. Up to now, various etching techniques including hyperthermal treatment by air or molecular oxygen, [19][20][21][22] ion bombardment, 23,24 oxygen plasma, [25][26][27][28][29][30] and wet chemical and electrochemical approaches 31 have been developed for this purpose. However, additional defects could be simultaneously introduced during the etching 25,26 due to the fast and vigorous interaction between carbon and these reactive species.…”

Shaping single crystalline BaTiO3 nanostructures by focused neon or helium ion milling

“…The Ne ions were directed outside the pillar region to mill around it. The presence of an amorphous region on the sidewalls and top of the pillars is due to lateral and backscattered ions [53]. This effect is typical for ion irradiation and has been also observed for Ga ions milling [54].…”