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, TN 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 Tb2Ti2O