Statics and dynamics of the highly correlated spin ice Ho2Ge2O7

The pyrochlore Ho2Ge2O7 is a new highly correlated spin ice material. Physical property measurements, including x-ray diffraction, dc susceptibility, and ac susceptibility, confirm that it shares the distinctive characteristics of other known spin ices. Polarized neutron scattering measurements on a powder sample, combined with reverse Monte Carlo (RMC) refinements, give unique information about the spin ice state in Ho2Ge2O7. RMC refinements are used to fit the powder magnetic diffuse scattering and predict the single-crystal magnetic scattering of Ho2Ge2O7, demonstrating consistency with spin ice behavior.