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Synthesis of Ba(Mg 1/3 Ta 2/3 )O 3 Microwave Ceramics through a Sol–Gel Route Using Acetate Salts
Author(s) -
Tsai ChienCheng,
Teng Hsisheng
Publication year - 2004
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.1151-2916.2004.tb06363.x
Subject(s) - sintering , materials science , sol gel , calcination , ceramic , crystallite , relative density , pellet , dielectric , grain size , chemical engineering , particle size , mineralogy , citric acid , inorganic chemistry , analytical chemistry (journal) , metallurgy , nanotechnology , composite material , chemistry , organic chemistry , catalysis , optoelectronics , engineering
A sol–gel process to unsophisticatedly synthesize Ba(Mg 1/3 Ta 2/3 )O 3 (BMT) ceramics at low cost has been developed in the present work. This process involves the reaction of TaCl 5 with acetates of Ba and Mg in the presence of citric acid. Pure BMT polycrystalline powders can be obtained by calcining the synthesized products at 1000°C. The BMT powders were found to have a primary particle size as small as 100 nm. BMT ceramics with favorable structural characteristics can be obtained from sintering of the sol–gel BMT at temperatures much lower than that for the conventional solid‐state BMT. Sintering the sol–gel BMT in pellet form at 1300°C resulted in an ordering parameter of 0.72 for the pellet, and a relative density of >95% was achieved with sintering at 1500°C. The grain size of the sintered sol–gel BMT was large and uniform in comparison with the products from the solid‐state method. Using the sol–gel route, sintering at temperatures as low as 1400°C gave ceramics with acceptable microwave dielectric properties (a dielectric constant of 16 and Qf factor of 14 400 GHz), while higher temperatures (>1600°C) are needed for the solid‐state route to give similar properties.