Probing the ground state of Gd2Sn2O7 through μSR measurements

We present μSR data recorded on a newly prepared sample of the geometrically frustrated magnetic material Gd2Sn2O7. These data confirm previously published results and clearly show that there is a dynamical component in the ground state. This seems in contrast to the result of the linear spin-wave calculation of A.G. Del Maestro and M.J.P. Gingras which predicts the spin-waves to be gapped over the whole first Brillouin zone with a gap larger than about 1.0K in temperature scale. The measured high-temperature paramagnetic spin dynamics is understood with a simple model. The conditions for observing a spontaneous magnetic field and a finite relaxation rate at low temperature are discussed in terms of the properties of a function which measures the density of fluctuation modes.