  Single crystals of PrNiO3 were grown under an oxygen pressure of 295 bar
using a unique high-pressure optical-image floating zone furnace. The crystals,
with volume in excess of 1 mm3, were characterized structurally using single
crystal and powder X-ray diffraction. Resistivity, specific heat, and magnetic
susceptibility were measured, all of which evidenced an abrupt, first order
metal-insulator transition (MIT) at ~130 K, in agreement with previous
literature reports on polycrystalline specimens. Temperature-dependent single
crystal diffraction was performed to investigate changes through the MIT. Our
study demonstrates the opportunity space for high fugacity, reactive
environments for single crystal growth specifically of perovskite nickelates
but more generally to correlated electron oxides.
