Chemical Preparation of Pb(Ni_(1/3)Nb_(2/3))O_3 Powders

摘要

A chemical preparation method was developed for the synthesis of lead nickel niobate (Pb(Ni_(l/3)Nb_(2/3))O_3, (PNN)) powders from nitrate solutions with Pb~(2+), Ni~(2+) and peroxo-Nb ions by hydrolysis with tetramethylammonium hydroxide ( (CH_3)_4NOH, TMAH) and/or diethylamine ( (C_2H_5)_2NH, DEA). The as-prepared powders were amorphous and consisted of very small particles (～30nm). A difference in compositional homogeneity of the coprecipitates was observed. Coprecipitates by DEA have a high degree of compositional homogeneity and high reactivities on calcination. The powders began to crystallize a cubic pyrochlore phase at 500℃ and yield 100% perovskite phase at 900℃. The process of transforming pyrochlore to perovskite was discussed.