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Seeding of Perovskite Lead Magnesium Niobate Crystallization from Pb‐Mg‐Nb‐EDTA Gels
Author(s) -
Narendar Yeshwanth,
Messing Gary L.
Publication year - 1999
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.1151-2916.1999.tb01983.x
Subject(s) - crystallization , nucleation , perovskite (structure) , seeding , pyrochlore , materials science , magnesium , chemical engineering , mineralogy , inorganic chemistry , chemistry , metallurgy , phase (matter) , organic chemistry , engineering , aerospace engineering
The addition of BaTiO 3 seed particles (50 nm in diameter) to a Pb‐Mg‐Nb‐EDTA solution (where EDTA represents ethylenediamine tetraacetic acid) reduces the formation temperature from 700°C to 600°C during combustion synthesis, because of epitaxial effects. The lower perovskite formation temperature eliminates the formation of pyrochlore at the surface of the precursor bed and allows for the direct crystallization of ∼98% perovskite lead magnesium niobate (PMN) during combustion synthesis. Increasing the nucleation density of the seed particles in the seeded precursor decreases the precursor volume that is associated with each perovskite nucleus and, thus, reduces the PMN particle size from 1 µm to 0.2 µm. The influence of BaTiO 3 seeding is discussed in terms of the thermodynamics of perovskite formation, the influence of BaTiO 3 seed concentration, and epitaxial nucleation.