Recent experiments on the quantum phase transition between nonmagnetic (x \leq x_c) and magnetically ordered (x > x_c) CeCu_6-xAu_x alloys, occurring at a critical concentration x_c \approx 0.1 are reviewed. In particular, we investigate how the q-dependence of the critical fluctuations observed for x = 0.1 by inelastic neutron scattering evolve when moving away from the critical concentration. We also explore the fluctuations when a magnetically ordered alloy (x = 0.2) is exposed to a magnetic field suppressing the magnetic order. Finally, we address the question whether at the quantum phase transition the Kondo temperature vanishes, i.e. the heavy quasiparticles loose their identity, as proposed by recent theories.

PACS numbers: 75.30.Mb, 71.27.+a, 71.10.Hf, 75.20.Hr