Comparative Study of the Synthesis of Ceramic Composites Based on Lanthanum Orthophosphate

Two approaches to the synthesis of nanosized precursor powders 0.5LaPO₄·nH₂O–0.5ZrO(OH)₂ and 0.5LaPO₄·nH₂O–0.5Y(OH)₃ for the fabrication of ceramic composites 0.5LaPO₄–0.5ZrO₂ and 0.5LaPO₄–0.5Y₂O₃ were used. In the first case, sol-gel synthesis of components (LaPO₄·nH₂O, ZrO(OH)₂ or Y(OH)₃) was carried out separately by reverse precipitation technique. In the second case, reverse precipitation was used too but without separate preparation of sols of the components. The results of the synthesis were compared by XRD analysis, thermal behavior of precursor powders by DSC/TG technique, as well as Vickers microhardness values of 0.5LaPO₄–0.5ZrO₂ and 0.5LaPO₄–0.5Y₂O₃ ceramic composites.