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Composition Inhomogeneity due to Alkaline Volatilization in Li ‐Modified ( K , Na ) NbO 3 Lead‐Free Piezoceramics
Author(s) -
Cheng LiQian,
Wang Ke,
Yao FangZhou,
Zhu Fangyuan,
Li JingFeng
Publication year - 2013
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/jace.12497
Subject(s) - x ray photoelectron spectroscopy , raman spectroscopy , volatilisation , sintering , phase (matter) , analytical chemistry (journal) , materials science , stoichiometry , chemistry , alkaline earth metal , mineralogy , alkali metal , chemical engineering , composite material , chromatography , physics , optics , organic chemistry , engineering
Alkaline volatilization during sintering in ( K , Na ) NbO 3 ( KNN )‐based lead‐free piezoceramics is a problem that causes non‐stoichiometry and hence affects the phase structures and properties. This work investigated the depth‐dependent distributions of alkaline elements in Li ‐modified KNN ceramics using X‐ray photoelectron spectroscopy and Raman spectroscopy. It was found that Li evaporated more severely than Na and K , consequently almost no Li elements remained on the as‐sintered surface, while its content became stable at the depth over 55 μm from the outmost surface. In addition, X‐ray diffraction results suggested the phase structure might show discrepancy at the pellet surface and the interior part due to the textured surface grains.