From antiferromagnetic and hidden order to Pauli paramagnetism in UM 2Si2 compounds with 5f electron duality

• Published in: Proceedings of the National Academy of Sciences - PNAS 2020-12, Vol.117 (48), p.30220-30227
• Main Authors: Amorese, Andrea, Sundermann, Martin, Leedahl, Brett, Marino, Andrea, Takegami, Daisuke, Gretarsson, Hlynur, Gloskovskii, Andrei, Schlueter, Christoph, Haverkort, Maurits W, Huang, Yingkai, Szlawska, Maria, Kaczorowski, Dariusz, Ran, Sheng, Maple, M Brian, Bauer, Eric D, Leithe-Jasper, Andreas, Hansmann, Philipp, Thalmeier, Peter, Tjeng, Liu Hao, Severing, Andrea
• Format: Article
• Language: English
• ISSN: 1091-6490
• DOI: 10.1073/pnas.2005701117

Using inelastic X-ray scattering beyond the dipole limit and hard X-ray photoelectron spectroscopy we establish the dual nature of the U [Formula: see text] electrons in U[Formula: see text] (M = Pd, Ni, Ru, Fe), regardless of their degree of delocalization. We have observed that the compounds have in common a local atomic-like state that is well described by the U [Formula: see text] configuration with the [Formula: see text] and [Formula: see text] quasi-doublet symmetry. The amount of the U 5[Formula: see text] configuration, however, varies considerably across the U[Formula: see text] series, indicating an increase of U 5f itineracy in going from M = Pd to Ni to Ru and to the Fe compound. The identified electronic states explain the formation of the very large ordered magnetic moments in [Formula: see text] and [Formula: see text], the availability of orbital degrees of freedom needed for the hidden order in [Formula: see text] to occur, as well as the appearance of Pauli paramagnetism in [Formula: see text] A unified and systematic picture of the U[Formula: see text] compounds may now be drawn, thereby providing suggestions for additional experiments to induce hidden order and/or superconductivity in U compounds with the tetragonal body-centered [Formula: see text] structure.