Browsing by Author "Morosan, E."
Now showing 1 - 2 of 2
- Results Per Page
- Sort Options
Item Ferromagnetic Ordering Along the Hard Axis in the Kondo Lattice YbIr₃Ge₇(American Physical Society) Rai, B. K.; Stavinoha, M.; Banda, J.; Hafner, D.; Benavides, Katherine A.; Sokolov, D. A.; Chan, Julia Y.; Brando, M.; Huang, C. -L; Morosan, E.; Benavides, Katherine A.; Chan, Julia Y.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.Item Intermediate Valence to Heavy Fermion Through a Quantum Phase Transition in Yb₃(Rh₁₋xTx)₄ Ge₁₃ (T = Co, Ir) Single Crystals(Amer Physical Soc, 2016-01-04) Rai, Binod K.; Oswald, Iain W. H.; Chan, Julia Y.; Morosan, E.; Oswald, Iain W. H.; Chan, Julia Y.Single crystals of Yb₃(Rh₁₋xTx)₄ Ge₁₃ (T = Co, Ir) have been grown using the self-flux method. Powder x-ray diffraction data on these compounds are consistent with the cubic structure with space group Pm3̅n. Intermediate-valence behavior is observed in Yb₃(Rh₁₋xTx)₄ Ge₁₃ upon T = Co doping, while T = Ir doping drives the system into a heavy-fermion state. Antiferromagnetic order is observed in the Ir-doped samples Yb₃(Rh₁₋xTx)₄ Ge₁₃ for 0.5 < x ≤ 1 with T_N = 0.96 K for Yb₃Ir₄Ge₁₃. With decreasing x, the magnetic order is suppressed towards a quantum critical point around x_c = 0.5, accompanied by non-Fermi-liquid behavior evidenced by logarithmic divergence of the specific heat and linear temperature dependence of the resistivity. The Fermi-liquid behavior is recovered with the application of large magnetic fields.