UPd(2)Al(3): An analysis of the inelastic neutron scattering spectra
The heavy fermion superconductor UPd(2)Al(3) exhibits the relatively uncommon combination of an antiferromagnetic phase transition, at T(N) = 14.3 K, followed by a superconducting phase transition below 2 K without destruction of the ordered magnetic moment. Neutron inelastic scattering at low energy transfers in the vicinity of the antiferromagnetic ordering wave vector has been used to probe the magnetic fluctuation spectrum in the temperature range 130 mK < T < 20 K. In the normal antiferromagnetic phase the spectra maybe characterized in terms of a damped spin wave interacting in a mean field manner with a quasielastic mode. By neutron polarization analysis the two modes have been shown to be polarized transverse to the sub-lattice magnetization vector. The spectra are used to estimate both the extrapolated low temperature linear term of the normal state heat capacity and the magnitude of T(N). Satisfactory agreement with the measured values is obtained. In the superconducting state at the lowest temperatures evidence is presented for the opening of a gap at low energies which may suggest a connection between the antiferromagnetic fluctuations and superconductivity.
Bibliographic Reference: Paper presented: Nato Advanced Study Institute, Moscow (RU), 1-5 September 1997
Availability: Available from (1) as Paper EN 41193 ORA
Record Number: 199810341 / Last updated on: 1998-03-09
Original language: en
Available languages: en