Neutron scattering investigations of the partially ordered pyrochlore Tb2Sn2O7

Neutron scattering measurements have been performed on polycrystalline Tb2Sn2O7 at temperatures above and below that of the phase transition, T-N = 0.87 K, to investigate further the spin dynamics in the magnetically ordered state. In particular, new neutron spin echo results are presented showing a dependence on Q in the dynamics. We show evidence of the coexistence of static ferromagnetism and dynamically fluctuating spins down to 30 mK and we make a comparison of this partially ordered system to the spin liquid Tb2Ti2O7.