Lattice parameters of (U, Pu, Am, Np)O2−x

The solid solutions of (U1−z−y'−y”PuzAmy'Npy”)O2−x (z = 0-1, y' = 0-0.12, y” = 0-0.07) were investigated by X-ray diffraction measurements, and a database for the lattice parameters was updated. A model to calculate the lattice parameters was derived from the database. The radii of the ions present in the fluorite structure of (U, Pu, Am, Np)O2−x were estimated from the lattice parameters measured in this work. The model represented the experimental data within a standard deviation of σ = ±0.025%.