title: Direct evidence for a dynamical ground state in the highly frustrated Tb(2)Sn(2)O(7) pyrochlore.
abstract: mSR experiments have been performed on a powder sample of the "ordered spin ice" Tb(2)Sn(2)O(7) pyrochlore. At base temperature (T=35 mK), the muon relaxation is found to be of dynamical nature, which demonstrates that strong fluctuations persist below the ferromagnetic transition (T(C)=0.87 K). Hints of long-range ordering appear as oscillations of the muon polarization when an external field is applied and also as a hysteretic behavior below T(C). We propose that dynamics results from fluctuations of clusters of correlated spins with the ordered spin ice structure.
authors.affiliation: Laboratoire de Physique des Solides, UMR 8502, Université Paris-Sud, 91405 Orsay, France.
authors.forename: F
authors.initials: F
authors.lastname: Bert
authors.forename: P
authors.initials: P
authors.lastname: Mendels
authors.forename: A
authors.initials: A
authors.lastname: Olariu
authors.forename: N
authors.initials: N
authors.lastname: Blanchard
authors.forename: G
authors.initials: G
authors.lastname: Collin
authors.forename: A
authors.initials: A
authors.lastname: Amato
authors.forename: C
authors.initials: C
authors.lastname: Baines
authors.forename: A D
authors.initials: AD
authors.lastname: Hillier