Siberian Federal University

The processes occurring during carbonization and subsequent mechanical activation of coprecipitated gadolinium and zirconium hydroxides, as well as their effect on the synthesis of Gd2Zr2O7 during thermal and autoclave treatment of the obtained precursors have been investigated. It has been revealed that when the coprecipitated hydroxides of Gd and Zr are saturated with carbon dioxide, crystalline hydrated gadolinium carbonate is formed. It has been shown that carbonization reduces the yield of gadolinium zirconate upon subsequent calcination of the precursor. As a result of autoclave treatment of the initial and carbonized precursor at 250 °C for 4 h, zirconium and gadolinium-containing phases crystallize separately, and Gd2Zr2O7 is not formed. After thermal treatment of the mechanically activated carbonized precursor at 900 °C for 3 h nanocrystalline fluorite-type Gd2Zr2O7 is formed with a yield of 100 %