Floating Zone Growth of Large Single Crystals of SrFeO₃-x

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.