Affiliation: | 1. Institute of Ion Beam Physics and Materials Research, Forschungszentrum Dresden-Rossendorf, 01314 Dresden, Germany;2. Research Inst. for Technical Phys. and Materials Sci., H-1525 Budapest, P.O. Box 49, Hungary;3. Aristotle University of Thessaloniki, Physics Department, 54006 Thessaloniki, Greece |