Soft mode and magnetic phase transition in PrNi

The spectrum of magnetic excitations in a single crystal of intermetallic compound PrNi was studied by inelastic neutron scattering. Experiment showed the substantial softening of some collective magnetic excitation modes near the ferromagnetic ordering temperature $T_c\approx20\,$K. The result is analyzed within the framework of a model that describes the magnetic phase transition in systems with induced magnetic moment.