  The Fe^{4+}-containing cubic perovskite phase SrFeO_3-x is of interest both
for its high-temperature, oxygen-conducting properties as a solid oxide fuel
cell component, and at low temperatures, where it exhibits a plethora of
helical magnetic phases and a candidate Skyrmion lattice. However, a sequence
of structural phase transitions encountered on cooling to room temperature has
limited the size of single crystals. We report the floating-zone growth and
oxygen-annealing of multiple-cubic-centimetre-sized single crystals of
SrFeO_3-x, suitable for inelastic neutron scattering and other measurement
techniques requiring large sample volumes.
