Magnetic fluctuations and the superconducting transition in the heavy-fermion material UPd2Al3

Inelastic neutron scattering has been performed on single crystals of the heavy-fermion superconductor UPd2Al3. The antiferromagnetically ordered state is characterized by an acoustic spin wave mode with no gap. The low-frequency magnitude excitations are unaffected by the transition to a superconducting state despite coupling to the conduction electrons as evidenced by the significant damping.