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Effects of MgO Stoichiometry on the Dielectric and Mechanical Response of Pb(Mg1/3Nb2/3)O3
Author(s) -
Koyuncu M.,
Pilgrim S. M.
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.tb02205.x
Subject(s) - stoichiometry , pyrochlore , columbite , dielectric , materials science , magnesium , diffraction , analytical chemistry (journal) , mineralogy , inorganic chemistry , chemistry , metallurgy , optics , chromatography , phase (matter) , organic chemistry , physics , optoelectronics
Careful control of the magnesia stoichiometry and hydration level overcomes the problem of pyrochlore formation in the synthesis of Pb(Mg 1/3 Nb 2/3 )O 3 (PMN). Careful removal of volatiles from MgO showed that excess MgO is not required to form pyrochlore‐free PMN using the columbite method; this clarifies the previously reported need of excess MgO. The stoichiometric PMN shows a peak dielectric constant of ~15 000 for 1 kHz. In addition, the presence of volatiles in the MgO has been linked with a change in fracture mode. The relation between the MgO stoichiometry and the microstructural and dielectric properties is presented in an integrated study using X‐ray diffraction at various temperatures, dielectric response, and microscopy.