An unconventional metallic state in YbRh2(Si1 xGex)2 a high pressure study

Abstract

We present a detailed pressure study of the electrical resistivity ρ(T) and the specific heat C(T) of the non-Fermi-liquid (NFL) compound YbRh₂Si₂ and of ρ(T) for a single crystal in which 5 at.% of Si is replaced by isoelectronic Ge. The magnetic phase diagram is deduced up to p ~ = 2.5 GPa. A comparison of the effects of the volume change introduced by doping and/or by hydrostatic pressure will be given. We show that the NFL behaviour observed in ρ(T) as well as the magnetic phase diagram are not influenced by the disorder introduced by alloying.