Rai, B. K.Stavinoha, M.Banda, J.Hafner, D.Benavides, Katherine A.Sokolov, D. A.Chan, Julia Y.Brando, M.Huang, C. -LMorosan, E.2019-12-182019-12-182019-03-182469-9950https://hdl.handle.net/10735.1/7140Due to copyright restrictions full text access from Treasures at UT Dallas is restricted to current UTD affiliates until 2020-03-18 (use the provided Link to Article).Ferromagnetic Kondo lattice compounds are far less common than their antiferromagnetic analogs. In this Rapid Communication, we report the discovery of a ferromagnetic Kondo lattice compound, YbIr₃Ge₇. As in almost all ferromagnetic Kondo lattice systems, YbIr₃Ge₇ shows magnetic order with moments aligned orthogonal to the crystal electric field (CEF) easy axis. YbIr₃Ge₇ is unique in that it is the only member of this class of compounds that crystallizes in a rhombohedral structure with a trigonal point symmetry of the magnetic site, and it lacks broken inversion symmetry at the local moment site. The ac magnetic susceptibility, magnetization, and specific heat measurements show that YbIr₃Ge₇ has a Kondo temperature TK≈14 K and a Curie temperature T_{C}=2.4K. Ferromagnetic order occurs along the crystallographic [100] hard CEF axis despite the large CEF anisotropy of the ground-state Kramers doublet with a saturation moment along [001] almost four times larger than the one along [100]. This implies that a mechanism which considers the anisotropy in the exchange interaction to explain the hard-axis ordering is unlikely. On the other hand, the broad second-order phase transition at T_{C} favors a fluctuation-induced mechanism. © 2019 American Physical Society.en©2019 American Physical SocietyAnisotropyAntiferromagnetismCrystallographyElectric fieldsFerromagnetic materialsFerromagnetismIridium compoundsMagnetic susceptibilitySpecific heatYtterbium compoundsRhombohedral structuresGermanium compoundsarticleRai, B. K., M. Stavinoha, J. Banda, D. Hafner, et al. 2019. "Ferromagnetic ordering along the hard axis in the Kondo lattice YbIr₃Ge₇." Physical Review B 99(12): art. 121109(R), doi: 10.1103/PhysRevB.99.1211099912