Susceptibility Maximum of Niobium Metal

At low temperatures the phenomenon of susceptibility maximum is universally observed in all paramagnetic 3d, 4d, and 5d metals except for niobium. We measured the temperature dependence of the magnetic susceptibility of niobium metal in various small magnetic fields very precisely by using a SQUID magnetometer. In niobium metal we have to consider the diamagnetic susceptibility due to superconducting fluctuations. We found that the susceptibility maximum was always observed when the applied field was lower than about 150 Oe. These results are consistent with Misawa's Fermi liquid theory.