Peculiarities of U-based Laves phases

Abstract

This contribution focuses on the structural and physical properties of U-based Laves phases. It starts with the structural description of the different type of Laves phases, followed by a brief description of the factors that affect their stability. The majority of the uranium Laves phases show a weakly paramagnetic behaviour. The reason is the compact structure of the phases that leads to small a U-U spacing as well as very high coordination numbers, regarding both the uranium and the ligands sublattices, which brings a strong hybridization with non- f states. However, there are some exceptions of uranium Laves phases that do order magnetically (UFe 2, UNi 2 and the recently discovered U 2Fe 3Ge compound). These exceptions are discussed in more detail in the present manuscript.