Antiferromagnetic order, magnetic instability and non-Fermi-liquid behavior in CeCu6-xAux: Tuning by Au concentration, hydrostatic pressure and magnetic field

CeCu6-xAux has become a prototype heavy-fermion system where, starting from not magnetically ordered CeCu6, Au doping introduces long-range incommensu rate antiferromagnetism for x > x(c) approximate to 0.1. At the critical co ncentration x(c), the unusual magnetic fluctuations probed by inelastic neu tron scattering lead to non-Fermi-liquid behavior, i.e. to anomalous low-te mperature thermodynamic and transport properties. In magnetically ordered a lloys, hydrostatic pressure can Le employed to tune the magnetic-nonmagneti c transition. The effect of pressure in suppressing the antiferromagnetic o rder is contrasted to the effect of a magnetic field by way of a detailed s tudy for x = 0.2.