Degiorgi, LeonardoOtt, Hans RudolfDressel, MartinGrüner, GeorgeFisk, Zachary2009-09-042016-03-312009-09-042016-03-311994316442348http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-46259http://elib.uni-stuttgart.de/handle/11682/7057http://dx.doi.org/10.18419/opus-7040We have investigated the complete electrodynamic response of the heavy-electron compounds U2Zn17 and UCu5. Particular emphasis has been devoted to the optical evidence of the antiferromagnetic phase transitions at 9.7 K and 15 K for U2Zn17 and UCu5, respectively. In UCu5, we found an absorption in the far infrared, which is ascribed to excitations across a spin-density-wave-type gap. This feature is absent in U2Zn17. We argue that UCu5 belongs to a characteristically different class of antiferromagnets than U2Zn17 which represents the class of heavy-electron compounds with localized magnetic moments.eninfo:eu-repo/semantics/openAccessSchwere-Fermionen-System , Antiferromagnetikum530article2010-09-28