Logarithmic Field Dependence of the Susceptibility of a Paramagnetic Fermi Liquid—the Pd Problem

The susceptibility χ(H) of a paramagnetic Fermi liquid in a magnetic field is shown to have the logarithmic form χ(H)=χ(0)(1-bH²lnH), and hence the free energy of the system cannot be expanded in powers of H or in powers of the magnetization. Contrary to the result of the band model, this prediction is consistent with the experimental field dependence observed in Pd.