Low-temperature topotactic oxidation using the solid-state oxidant Zr-doped CeO2.

A new topotactic oxidation was developed using the solid-state oxidant Zr-doped CeO2. For the anti-ThCr2Si2 type Y2O2Bi, which became superconducting via oxygen intercalation during solid-state oxidation at 1000 °C, the topotactic oxidation enabled not only the oxygen intercalation at a much lower temperature of 200 °C, hampering the segregation of impurity phases, but also the highest superconducting transition temperature for Y2O2Bi.