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Chemical Preparation of Lead‐Containing Niobate Powders
Author(s) -
Yoshikawa Yoshio,
Uchino Kenji
Publication year - 1996
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1996.tb08991.x
Subject(s) - calcination , aqueous solution , pyrochlore , perovskite (structure) , inorganic chemistry , niobium , materials science , precipitation , dissolution , nitric acid , ammonia , hydrolysis , nuclear chemistry , phase (matter) , chemistry , catalysis , crystallography , metallurgy , organic chemistry , physics , meteorology
A chemical precipitation method was developed for synthesis of typical relaxor compounds—Pb(Mg 1/3 Nb 2/3 )O 3 (PMN), Pb(Fe 1/2 Nb 1/2 )O 3 (PFN), and Pb(Sc 1/2 Nb 1/2 )O 3 (PSN)—from nitrate solutions. To obtain a niobium precursor compatible with the aqueous chemical routes, peroxo‐niobium complex solutions were prepared by dissolving hydrated niobia precipitates in a dilute nitric acid solution with hydrogen peroxide. Powders that consisted of small particles ranging from 20 to 40 nm were successfully precipitated from the mixed nitrate solutions by hydrolysis with aqueous ammonia solutions. On calcination, these powders were highly reactive. For example, PMN precursor powder began to crystallize simultaneously to cubic pyrochlore and perovskite phases at ∼400°C and yielded ∼95% of the perovskite phase after calcination at 800°C for 1 h. PFN and PSN precursor powders calcined under similar conditions formed single perovskite phases.