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 sigma = +/-0.025%.