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Spray Pyrolysis Synthesis and Dielectric Properties of Pb(Mg 1/3 Nb 2/3 )O 3
Author(s) -
Zhou XiaoDong,
Zhang ShiChang,
Huebner Wayne
Publication year - 2008
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.1551-2916.2008.02519.x
Subject(s) - materials science , pyrochlore , dielectric , nanocrystalline material , crystallite , grain size , grain boundary , perovskite (structure) , analytical chemistry (journal) , calcination , ceramic , mineralogy , sintering , chemical engineering , aqueous solution , phase (matter) , microstructure , metallurgy , chemistry , nanotechnology , organic chemistry , optoelectronics , engineering , catalysis
Spray pyrolysis was used to synthesize lead magnesium niobate (PMN) by atomizing a mixture of nitrate aqueous solutions into a high‐temperature furnace. This approach allows for instant removal of solvents and decomposition of metal–salts, thereby limiting phase segregation on a nanometer scale, and lowering the transformation temperature for pyrochlore‐to‐perovskite phase transition. As‐synthesized particles were nanocrystalline pyrochlores, with an average crystallite size ∼22 nm. More than 96% perovskite phase was obtained when as‐sprayed powders were subsequently calcined at 750°C for 4 h. Sintered PMN ceramics exhibited the typical frequency‐dependent dielectric properties, with a peak value of dielectric constant of 18 000, and a transition temperature at −9.6°C at 100 Hz. A series of ceramics were prepared with varied grain sizes. Increasing the grain size increased the dielectric constant, probably due to the smaller fraction of the less‐polarizable grain‐boundary phases.