2008/09/30 by Y. Tokiwa, T. Radu, Teodora Radu +3 · 4 citations
Materials Science · Physics and Astronomy · #Iron-based superconductors research #Organic and Molecular Conductors Research #Rare-earth and actinide compounds #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.102.066401
published as Phys. Rev. Lett. 102, 066401 (2009) · 4 pages, 3 Figures
arxiv created 2008/11/26 · openalex publication_date 2009/02/10 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
The heavy-fermion metal YbRh2Si2 is studied by low-temperature magnetization M(T) and specific-heat C(T) measurements at magnetic fields close to the quantum critical point (Hc=0.06 T, H\ensuremath⊥c). Upon approaching the instability, dM/dT is more singular than C(T), leading to a divergence of the magnetic Gr"uneisen ratio \ensuremathΓmag=\ensuremath-(dM/dT)/C. Within the Fermi-liquid regime, \ensuremathΓmag=\ensuremath-Gr(H\ensuremath-Hcfit) with Gr=\ensuremath-0.30\ifmmode±\else\textpm\fi0.01 and Hcfit=(0.065\ifmmode±\else\textpm\fi0.005) T which is consistent with scaling behavior of the specific-heat coefficient in YbRh2(Si0.95Ge0.05)2. The field dependence of dM/dT indicates an inflection point of the entropy as a function of magnetic field upon passing the line T^\ensuremath⋆(H) previously observed in Hall and thermodynamic measurements.