Quantum phase transition in the heavy-fermion compound YbIr$_2$Si$_2$

H. Q. Yuan; M. Nicklas; Z. Hossain; C. Geibel; F. Steglich

doi:10.1103/PhysRevB.74.212403

paper

Quantum phase transition in the heavy-fermion compound YbIr $_{2}$ Si $_{2}$

arXiv:cond-mat/0610126 · doi:10.1103/PhysRevB.74.212403

Abstract

We investigate the pressure-temperature phase diagram of YbIr $_{2}$ Si $_{2}$ by measuring the electrical resistivity $I ¨ (T)$ . In contrast to the widely investigated YbRh $_{2}$ Si $_{2}$ , YbIr $_{2}$ Si $_{2}$ is a paramagnetic metal below $p_{c} ≃ 8$ GPa. Interestingly, a first-order, presumably ferromagnetic, transition develops at $p_{c}$ . Similar magnetic properties were also observed in YbRh $_{2}$ Si $_{2}$ and YbCu $_{2}$ Si $_{2}$ at sufficiently high pressures, suggesting a uniform picture for these Yb compounds. The ground state of YbIr $_{2}$ Si $_{2}$ under pressure can be described by Landau Fermi-liquid (LFL) theory, in agreement with the nearly ferromagnetic Fermi-liquid (NFFL) model. Moreover, evidence of a weak valence transition, characterized by a jump of the Kadowaki-Woods (KW) ratio as well as an enhancement of the residual resistivity $I ¨ _{0}$ and of the quasiparticle-quasiparticle scattering cross section, is observed around 6 GPa.

4 pages, 5 figures

Quantum phase transition in the heavy-fermion compound YbIr2​Si2​

Abstract

Quantum phase transition in the heavy-fermion compound YbIr $_{2}$ Si $_{2}$