[en] Be- and Ce-2-4-pentanedionates were reacted with Zr-tetra-n-butoxide in anhydrous ethanol to deliver gels which were used as precursors of very reactive oxide mixtures. Compositions of the ternary system rapidly reached equilibrium conditions, even at low temperatures. X-ray and microscopy evidence confirmed that BeO was not part of the CeO2-ZrO2 solid solutions. (author)