On the magnetic field dependence of the susceptibility at the quantum critical point in CeCu5.9Au0.1

Magnetization measurements and the field dependence of 63Cu NMR relaxation rates are used to analyse the effect of an external
magnetic field H at the quantum critical point of CeCu5.9Au0.1. It is argued that the scaling argument in which H is included through an effective temperature Teff holds only in weak field, while in strong fields the data are rather accounted for by direct scaling
of the field dependence of magnetization.