Magnetic Properties of a Pressure-induced Superconductor UGe₂

Abstract

We performed DC-magnetization and neutron scattering experiments under pressure P for a pressure-induced superconductor UGe₂. We found that the magnetic moment is enhanced at a characteristic temperature T^* in the ferromagnetic state, where T^* is smaller than a Curie temperature T_C. This enhancement becomes remarkable in the vicinity of P_C^*=1.20 GPa, where T^* becomes 0 K and the superconducting transition temperature T_SC shows a maximum. The characteristic temperature T^*, which decreases with increasing pressure, also depends on the magnetic field.