Spin dynamics of quadrupole-ordered PrFe4P12

PrFe4P12 shows a unique transition at 6.5 K with clear anomalies in its bulk properties. In order to understand the nature of the transition, we have undertaken inelastic neutron scattering studies from 300 to 2 K with varying magnetic fields up to 7 T. The analysis of the present data demonstrates that there is a pronounced change of the spin dynamics at 6.5 K which we attribute to the interplay between the spin and quadrupole degrees of freedom. (c) 2005 Elsevier B.V. All rights reserved.