Physical–chemical properties of nanopowders and ceramic samples of REE orthophosphates

Abstract

A series of physical–chemical studies of a series of binary REE orthophosphate systems has been performed: LaPO₄–DyPO₄–H₂O, LaPO₄–YPO₄–H₂O, LaPO₄–LuPO₄–H₂O, YPO₄–LuPO₄–H₂O, and YPO₄–ScPO₄–H₂O. Nanopowders of Ln'_{1 −x}Ln'_x PO₄ · nH₂O orthophosphates have been synthesized by the sol–gel method using direct and reverse precipitation techniques. Ceramic samples were produced from the nanopowders, and their physical–mechanical properties were determined depending on the thermal treatment temperature and duration. The ceramic samples’ thermal behavior has been investigated by the dilatometry method. The results have been compared depending on the technique of nanopowder synthesis.