Localized moments and the stability of antiferromagnetic order in Yb3Pt4

Abstract

We present here the results of electrical resistivity ρ, magnetization M, ac susceptibility χ ′ ac , and specific heat CM measurements that have been carried out on single crystals of Yb3Pt4 over a wide range of fields and temperatures. The 2.4 K Néel temperature that is found in zero field collapses under field to a first order transition TN = 0 at BCEP = 1.85 T. In the absence of antiferromagnetic order, the specific heat CM(T, B), the magnetization M (T, B), and even the resistivity ρ(T, B) all display B/T scaling, indicating that they are dominated by strong paramagnetic fluctuations, where the only characteristic energy scale results from the Zeeman splitting of an energetically isolated, Yb doublet ground state. This paramagnetic scattering disappears with the onset of antiferromagnetic order, revealing Fermi liquid behavior ∆ρ = AT 2 that persists up to the antiferromagnetic phase line TN(B), but not beyond. The first order character of TN = 0 and the ubiquity of the paramagnetic fluctuations imply that non-Fermi liquid behaviors are absent in Yb3Pt4. In contrast to heavy fermions like YbRh2Si2, Yb3Pt4 represents an extremely simple regime of f -electron behavior where the Yb moments and conduction electrons are almost decoupled, and where Kondo physics plays little role.

Tuning of 4f- and Fe-based correlated electron systems by magnetic field and chemical substitution

“…5.23 is more consistent with a quantum phase transition, similar to what are shown in Refs. [186] and [188], that does not manifest any critical behavior. It becomes evident that CeZn 11 manifests a local moment-like, metamagnetic phase transition as a function of field.…”