Synthesis and thermal decomposition of mixed Gd-Nd oxalates

Several (Gd_1−xNd_x)₂C₂O₄]₃·nH₂O samples (0≤x≤1) were prepared by a coprecipitation method: the precipitation is quantitative and all the samples are homogeneous in stoichiometry. XRD analyses have shown that a complete solid solution is formed over the whole range of compositions. The dried Gd rich oxalates have initially a low water content which gradually increases with the Nd content. All the oxalates decompose in O₂ around 700°C either into a single mixed oxide or in a mixture of oxides through several steps, which can be ascribed to the loss of water and CO₂.