Low temperature stabilization of zirconia by Mn through Co-precipitated hydroxide gel route

Stabilization of zirconia into cubic phase is achieved by partly substituting Zr⁴⁺ with Mn⁴⁺ ions (5–30 mole %) via hydroxide gel formation and subsequent calcination at 773 K and is supported by XRD and IR data. A linear correlation between the lattice parameter and the Mn content confirms the incorporation of Mn into ZrO₂. The XPS and TPR results provide some evidence for the presence of Mn⁴⁺ ions in these samples which have a surface area of about 100 m² g^-1 and are stable in the cubic phase up to 973 K. On reduction above 973 K, the cubic phase is stabilized probably by Mn²⁺ ions.