Phase diagram of the heavy fermion system YbFe/sub 2/Ge/sub 2/ under pressure

Abstract

The phase diagram of the heavy fermion compound YbFe2Ge2 under high pressures P ≤ 18.2 GPa was obtained by electrical resistivity measurements. Pressure drives the system from a paramagnetic Fermi liquid state to a magnetically ordered state, with a quantum critical point at PC ≈ 9.4 GPa. In the vicinity of PC a non-Fermi-liquid behavior ascribed to two-dimensional antiferromagnetic fluctuations is observed. In the magnetic side, the resistivity shows the existence of spin-wave excitations characteristic of an antiferromagnet