Radiation defects in nano-structured materials H. Ohtsuka, K. Hojou, H. Maeta, H. Otsu, H. Sugai and H. Yamamoto Eur. Phys. J. D, 16 1-3 (2001) 309-311 Published online: 15 September 2001 DOI: 10.1007/s100530170117