A high-temperature neutron diffraction study of pure and scandia-stabilized zirconia

A high-temperature neutron diffraction apparatus has been used to study a section of the zirconia-scandia system; the purpose was to determine whether this technique can be generally applied to phase equilibria studies. The structure of the tetragonal form of zirconia at 1200°C has been confirmed, and the parameters obtained were z(4d) = 0.188 ± 0.002, B₀ = 2.50Ų, B_Zr = 0.80 Ų, and R = 0.045. The effect of substituting scandia into the tetragonal zirconia structure was studied and the transformation of the ordered low-temperature β-phase to a grossly nonstoichiometric fluorite phase was also observed.