The uranium Laves phase UFe(2) was prepared by ultrafast cooling which allows to incorporate excessive Fe of about 0 3 Fe/fu into the nanocrystalline Laves phase structure (57)Fe Mossbauer spectroscopy reveals that such Fe atoms occupy the U sites Stronger magnetic hyperfine field points to larger Fe moments of such antistructure Fe Higher Fe excess leads to its segregation in the form of alpha-Fe The Curie temperature of the UFe(2+x) phase increases to the limit value 230-240 K (C) 2010 Elsevier Ltd All rights reserved