We investigate the intermixing of layers in Sc/Si and Sc/B(4)C/Si/B(4)C multilayers using electron and synchrotron excited soft X-ray emission and absorption spectroscopy. The multilayers are annealed at 100, 200, 300, 400 and 500 degrees C after preparation by magnetron sputtering. Silicon K(beta) emission and reflectivity measurements verify that the non-annealed multilayer systems are composed of distinct layers with only a minor interdiffusion in Sc/Si samples whereas annealing Sc/Si multilayers at 400 degrees C leads to a degradation of the multilayer structure and the formation of intermittent scandium silicide, ScSi. The presence of B(4)C barriers in Sc/B(4)C/Si/B(4)C hinders this degradation from developing for the entire temperature range considered. The barrier layers continue to be effective for the entire temperature range even after an extended shelf-life. (C) 2010 Elsevier B.V. All rights reserved.