  Superconducting states onsetting at moderately high temperatures have been
observed in epitaxially-stabilized RENiO2-based thin films. However, recently
it has also been reported that superconductivity at high temperatures is
observed in bulk La3Ni2O7-{\delta} at high pressure, opening further
possibilities for study. Here we report the reduction profile of La3Ni2O7 in a
stream of 5% H2/Ar gas and the isolation of the metastable intermediate phase
La3Ni2O6.45, which is based on Ni2+. Although this reduced phase does not
superconduct at ambient or high pressures, it offers insights into the Ni-327
system and encourages the future study of nickelates as a function of oxygen
content.
