Magnetic order in UO(2) and NpO(2) studied by muon spin rotation
Muon spin rotation/relaxation (µSR) measurements were carried out in zero applied field on NpO(2) and UO(2) above and below their transition temperatures of 25 K and 30.8 K, respectively. In NpO(2) a spontaneous spin precession pattern is observed for T< 25 K. The data are compared to analogous results on isostructural UO(2) where the 30.8 K transition is well established as the Néel temperature for antiferromagnetic order. The µSR patterns are in their basic features quite alike for the two compounds. This establishes unambiguously that the transition at 25 K in NpO(2) is basically of magnetic origin. The ordered moment on Np is estimated to be smaller than about 0.15 µ(B), ie. less than 10% of the moment on U in antiferromagnetic UO(2).
Bibliographic Reference: Paper presented: Actinides '97, Baden-Baden (DE), 21-26 September 1997
Availability: Available from (1) as Paper EN 41105 ORA
Record Number: 199810227 / Last updated on: 1998-03-09
Original language: en
Available languages: en