Evolution from Ferromagnetism to Antiferromagnetism in Yb(Rh1-xCox)2Si2

Abstract

Yb(Rh1-xCox)2Si2 is a model system to address two challenging problems in the field of strongly correlated electron systems: The first is the intriguing competition between ferromagnetic (FM) and antiferromagnetic (AFM) order when approaching a magnetic quantum critical point (QCP). The second is the occurrence of magnetic order along a very hard crystalline electric field (CEF) direction, i.e. along the one with the smallest available magnetic moment. Here, we present a detailed study of the evolution of the magnetic order in this system from a FM state with moments along the very hard c direction at x = 0.27 towards the yet unknown magnetic state at x = 0. We first observe a transition towards an AFM canted state with decreasing x and then to a pure AFM state. This confirms that the QCP in YbRh2Si2 is AFM, but the phase diagram is very similar to those observed in some inherently FM systems like NbFe2 and CeRuPO, which suggests that the basic underlying instability might be FM. Despite the huge CEF anisotropy the ordered moment retains a component along the c-axis also in the AFM state. The huge CEF anisotropy in Yb(Rh1-xCox)2Si2 excludes that this hard-axis ordering originates from a competing exchange anisotropy as often proposed for other heavy-fermion systems. Instead, it points to an order-by-disorder based mechanism.

arXiv comment6 pages, 4 figures

References in corpus (23)

• Fermi-liquid instabilities at magnetic quantum phase transitions
• Quantum Criticality in Heavy Fermion Metals
• The break up of heavy electrons at a quantum critical point
• Hall-effect evolution across a heavy-fermion quantum critical point
• Magnetic-Field Induced Quantum Critical Point in YbRh${}_2$Si${}_2$
• Metallic Quantum Ferromagnets
• Nonanalytic behavior of the spin susceptibility in clean Fermi systems
• Fermi-surface collapse and dynamical scaling near a quantum critical point
• Ferromagnetic quantum critical fluctuations in YbRh_2(Si_{0.95}Ge_{0.05})_2
• Quantum Tricritical Points in NbFe${}_2$
• Spin Fluctuation Theory for Quantum Tricritical Point Arising in Proximity to First-Order Phase Transitions: Applications to Heavy-Fermion Systems, YbRh2Si2, CeRu2Si2, and beta-YbAlB4
• From incommensurate correlations to mesoscopic spin resonance in YbRh2Si2
• Evolution of magnetism in Yb(Rh_(1-x)Co_x)2Si2
• Single crystal growth and anisotropy of CeRuPO
• YbRh2Si2: Quantum tricritical behavior in itinerant electron systems
• Pressure-Temperature-Magnetic Field Phase Diagram of Ferromagnetic Kondo Lattice CeRuPO
• Magnetic hard-axis ordering near ferromagnetic quantum criticality
• GdRh${}_2$Si${}_2$: An exemplary tetragonal system for antiferromagnetic order with weak in-plane anisotropy
• Magnetic ordering with reduced cerium moments in hole-doped CeOs2Al10
• Competing orders, competing anisotropies, and multicriticality: The case of Co-doped YbRh2Si2
• Complex and strongly anisotropic magnetism in the pure spin system EuRh2Si2
• Electron Spin Resonance of the Yb 4f moment in Yb(Rh1-xCox)2Si2
• Spin-flip scattering of critical quasiparticles and the phase diagram of YbRh2Si2

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• Origin of the non-Fermi-liquid behavior in CeRh2As2
• Electro-nuclear transition into a spatially modulated magnetic state in YbRh${}_2$Si${}_2$
• Tuning low-energy scales in YbRh${}_2$Si${}_2$ by non-isoelectronic substitution and pressure
• Suppression of antiferromagnetic order and strong ferromagnetic spin fluctuations in Ni-doped CaCo2As2 single crystals