Fingering instabilities of a reactive micellar interface

International audienc

Depth profiling studies of multilayer films with a C 60 þ ion source

Abstract A newly developed C 60 þ primary ion beam source for time-of-flight secondary ion mass spectrometry has been employed for depth profiling analysis of organic and inorganic multilayer films. In particular, the C 60 þ ion beam is used in the dc mode to sputter the surface for depth profiling while spectra are taken both with Ga þ 15 keV and C 60 þ 20 keV projectiles between sputtering cycles. From C 60 þ bombardment of Langmuir-Blodgett films of barium arachidate, we find that cluster beams increase the secondary ion yields and ion formation efficiencies compared to monoatomic projectiles. For a 15-layer film, a barium arachidate fragment ion at m/z ¼ 208:9 was monitored as a function of C 60 þ dose to determine that the sputtering rate is about 1.54 nm/s and that the film interface position can be determined with a depth resolution of 16 nm. For comparison purposes, a depth resolution of 8.7 nm was measured for a sample consisting of 66 nm of Ni and 53 nm of Cr on Si(1 0 0) at a C 60 þ beam energy of 20 keV. The neutral atom yield was monitored via laser postionization to avoid matrix effects. These experiments show great promise for the use of C 60 þ for depth profiling studies of multilayer targets.

Chemistry and sputtering induced by fullerene and argon clusters in carbon-based materials

Classical MD computer simulations are used as a tool for the theoretical investigation of the processes initiated in carbonbased materials by the irradiation with C60 and Arn clusters. This paper shows the comparison of data regarding the chemical reactions occurring in polystyrene and fullerite bombarded by C60 and Arn projectiles with the initial energy of 2.5 and 10 keV. Its main focus is to elucidate the influence of material type on the bond breaking as new bond formation processes induced by impinging cluster projectiles