Non-collinear ferromagnetism in the Kondo lattice Ce${}_5$CoGe${}_2$

Abstract

The dense Kondo lattice Ce${}_5$CoGe${}_2$ exhibits superconductivity once the magnetic ordering is suppressed by pressure. Here the ambient pressure magnetic state is investigated via magnetization, heat capacity, powder neutron diffraction, and muon spin relaxation ($\mu$SR) measurements. Neutron diffraction results reveal a noncollinear ferromagnetic structure, where the four inequivalent Ce sites exhibit different magnetic moments. Point-charge model calculations of the crystalline-electric field (CEF) ground states corroborate different moments between the sites, and suggest sizeable components of the moments along different directions, consistent with the non-collinear structure. Analysis of the Dzyaloshinskii-Moriya (DM) interaction for the bonds connecting Ce atoms demonstrates that most of these bonds exhibit a nonzero DM vector, suggesting that competition between intersite magnetic exchange interactions, CEF driven single-ion anisotropy, the Kondo effect and the DM interaction may drive the non-collinear ferromagnetism.

11 pages, 6 figures

References in corpus (23)

• Advances in the Physics of Magnetic Skyrmions and Perspective for Technology
• Quantum Criticality in Heavy Fermion Metals
• Heavy Fermions and Quantum Phase Transitions
• Physical foundations and basic properties of magnetic skyrmions
• Topological Magnetic Phase in the Candidate Weyl Semimetal CeAlGe
• Multiple quantum phase transitions and superconductivity in Ce-based heavy fermions
• Ferromagnetic Quantum Critical Point Avoided by the Appearance of Another Magnetic Phase in LaCrGe${}_3$ under Pressure
• Anisotropic c-f hybridization in the ferromagnetic quantum critical metal CeRh${}_6$Ge${}_4$
• Properties of Ferromagnetic Superconductors
• Avoided ferromagnetic quantum critical point in CeRuPO
• Formation of short-range magnetic order and avoided ferromagnetic quantum criticality in pressurized LaCrGe${}_3$
• Localized 4f-electrons in the quantum critical heavy fermion ferromagnet CeRh${}_6$Ge${}_4$
• Magnetic order and crystalline electric field excitations of the quantum critical heavy fermion ferromagnet CeRh${}_6$Ge${}_4$
• Unveiling the Hybridization Process in a Quantum Critical Ferromagnet by Ultrafast Optical Spectroscopy
• A unified theory of ferromagnetic quantum phase transitions in heavy fermion metals
• Instability of the ferromagnetic quantum critical point in strongly interacting 2D and 3D electron gases with arbitrary spin-orbit splitting
• Ce-site dilution in the ferromagnetic Kondo lattice CeRh${}_6$Ge${}_4$
• Probing quantum criticality in ferromagnetic CeRh6Ge4
• Magnetic field-induced softening of spin waves and hard-axis order in Kondo-lattice ferromagnet CeAgSb${}_2$
• Suppression of ferromagnetism and influence of disorder in silicon-substituted CeRh6Ge4
• The influence of magnetic sublattice dilution on magnetic order in CeNiGe3 and UNiSi2
• Evidence for easy-plane XY ferromagnetism in heavy-fermion quantum-critical CeRh6Ge4
• From localized 4f electrons to anisotropic exchange interactions in ferromagnetic CeRh6Ge4