  We report a structural and thermodynamic study of the "stuffed spin ice"
material Ho2TiO5 (i.e., Ho2(Ti1.33Ho0.67)O6.67), comparing samples synthesized
through two different routes. Neutron powder diffraction and electron
diffraction reveal that the previously reported defect fluorite phase has
short-range pyrochlore ordering, in that there are domains in which the Ho and
Ho/Ti sublattices are distinct. By contrast, a sample prepared through a
floating zone method has long range ordering of these sublattices. Despite the
differences in crystal structures, the two versions of Ho2TiO5 display similar
magnetic susceptibilities. Field dependent magnetization and measured recovered
entropies, however, show a difference between the two forms, suggesting that
the magnetic properties of the stuffed pyrochlores depend on the local
structure.
