Diffusion of barium ions in the Ba3-3xLa2x square(x)(VO4)(2) solid solution

Diffusion coefficients for Ba-133, Sr-90, and Ca-45 radionuclides in the so lid solution Ba(3-3x)La(2x)rectangle(x)(VO4)(2) (x = 0, 0.05, 0.1, 0.15) ar e measured in the temperature range 800 to 1000 degrees C using the layer-b y-layer radiometric analysis. It is established that D-Ca(*) greater than o r equal to D-Sr(*) > D-Ba(*). Increasing the concentration of vacancies rec tangle in the barium sublattice leads to an increase in the diffusion coeff icients of the alkaline-earth metal cations. The activation energies for th e radionuclide diffusion are determined; their values (similar or equal to 1.1 eV) are close to the activation energy for ionic conduction. Cations M2 + are shown to migrate via the positions of Ba(2).