  We report the optimized conditions for growing the high quality single
crystals of candidate quantum spin-ice Pr2Hf2O7 using the optical floating-zone
method. Large single crystals of Pr2Hf2O7 have been grown under different
growth conditions using a four-mirror type optical floating-zone furnace and
their microscopic structural differences have been probed by high-resolution
synchrotron x-ray diffraction (SXRD). The SXRD data reveal that the crystals
grown under fowing argon (~ 2 L/h) atmosphere with slightly off-stoichiometric
(optimized) starting composition yields the highest quality crystals. The
magnetic susceptibility, isothermal magnetization and heat capacity data of
optimally grown crystals are presented.
