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Calcium‐Ion Selective Site Occupation at Ruddlesden‐Popper‐Type Faults and the Resultant Dielectric Properties of A‐Site‐Excess Strontium Calcium Titanate Ceramics
Author(s) -
Fujimoto Masayuki,
Suzuki Toshimasa,
Nishi Yuji,
Arai Katsuhiko,
Tanaka Junzo
Publication year - 1998
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.1151-2916.1998.tb02292.x
Subject(s) - strontium , dielectric , calcium titanate , calcium , strontium titanate , materials science , mineralogy , analytical chemistry (journal) , microstructure , titanate , ceramic , ion , chemistry , composite material , metallurgy , optoelectronics , organic chemistry , chromatography
The microstructure and dielectric properties of A‐site‐excess and stoichiometric‐composition strontium calcium titanate ((Sr,Ca)TiO 3 ) ceramics were investigated in the present study. Ruddlesden‐Popper‐type planar faults in A‐site‐excess specimens were observed using high‐resolution scanning transmission electron microscopy (HR‐STEM). STEM microchemical analysis, calculation of the high‐resolution image using a multislice method, and structural‐energy calculation further revealed that calcium ions selectively occupied the cation sites of the faults. An observed shift of the peak dielectric constant to low temperature and the expansion of the lattice parameter of the A‐site‐excess specimen were attributed to the selective occupation of the cation sites of the planar faults by calcium ions.