Measurement of beryllium depth profiles in carbon

This paper is concerned with the measurement of Be diffusion profiles in C by combining RBS and XPS sputter depth profiling. The total Be content in the samples was measured by RBS (2 MeV He-4(+)) at a scattering angle of 102degrees in order to increase depth resolution and sensitivity for Be. To apply a depth scale to the XPS sputter profiles measured using 3 keV Ar+ at 45degrees angle of incidence, the Monte-Carlo code TRIDYN was used to calculate the surface recession as a function of surface composition. The so obtained high resolution depth profiles were then scaled in such a way that their integrals would correspond to the total amount of Be as measured by RBS. From these diffusion profiles of Be in C the concentration-dependent inter-diffusion coefficient D(c) was determined by applying Boltzmann-Matano analysis. We found that O impurities have an appreciable influence on the diffusion of Be into C namely the diffusion is increased by a factor of similar to2 when O is present at the Be/C interface. (C) 2004 Elsevier B.V. All rights reserved.