Crystal-field states of Pr3+ in the candidate quantum spin ice Pr2Sn2O7

Neutron time-of-flight spectroscopy has been employed to study the crystal-field splitting of Pr3+ in the pyrochlore stannate Pr2Sn2O7. The crystal field has been parameterized from a profile fit to the observed neutron spectrum. The single-ion ground state is a well-isolated non-Kramers doublet of Gamma(+)(3) symmetry with a large Ising-like anisotropy,chi(zz)/chi(perpendicular to) approximate to 60 at 10 K, but with a significant admixture of terms |M-J not equal +/- J >, which can give rise to quantum zero-point fluctuations. This magnetic state satisfies the requirements for quantum spin-ice behavior.