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arXiv · 1504.00612

Avoided ferromagnetic quantum critical point in CeRuPO

E. Lengyel·M. E. Macovei·A. Jesche·C. Krellner·C. Geibel·M. Nicklas
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Abstract

CeRuPO is a rare example of a ferromagnetic (FM) Kondo-lattice system. External pressure suppresses the ordering temperature to zero at about $p_c\approx3$ GPa. Our ac-susceptibility and electrical-resistivity investigations evidence that the type of magnetic ordering changes from FM to antiferromagnetic (AFM) at about $p^*\approx0.87$ GPa. Studies in applied magnetic fields suggest that ferromagnetic and antiferromagnetic correlations compete for the ground state at $p>p^*$, but finally the AFM correlations win. The change in the magnetic ground-state properties is closely related to the pressure evolution of the crystalline-electric-field level (CEF) scheme and the magnetic Ruderman-Kittel-Kasuya-Yosida (RKKY) exchange interaction. The Néel temperature disappears abruptly in a first-order-like fashion at $p_c$, hinting at the absence of a quantum critical point. This is consistent with the low-temperature transport properties exhibiting Landau-Fermi-liquid (LFL) behavior in the whole investigated pressure range up to 7.5 GPa.

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E. Lengyel, M. E. Macovei, A. Jesche, C. Krellner, C. Geibel, M. Nicklas. 2015-04-02. Avoided ferromagnetic quantum critical point in CeRuPO. https://doi.org/10.1103/physrevb.91.035130

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