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Ordered Structure and Dielectric Properties of Lanthanum‐Substituted Ba(Mg 1/3 Ta 2/3 )O 3
Author(s) -
Tien LaiCheng,
Chou ChenChia,
Tsai DahShyang
Publication year - 2000
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.1151-2916.2000.tb01514.x
Subject(s) - lanthanum , crystal structure , crystallography , dielectric , materials science , solid solution , perovskite (structure) , phase (matter) , analytical chemistry (journal) , chemistry , inorganic chemistry , metallurgy , optoelectronics , organic chemistry , chromatography
Both 1:2 and 1:1 ordered structures form in the perovskite solid solutions of La‐substituted BMT Ba 1− x La x (Mg (1+ x )/3 Ta (2− x )/3 )O 3 , sintered at 1600°C. The 1:2 ordered structure exists in the composition range 0.0 ≤ x ≤ 0.12, while that of 1:1 ordered structure exists in a wider composition range 0.04 ≤ x ≤ 1.0. Two ordered phases coexist in 0.04 ≤ x ≤ 0.12. High‐resolution micrographs indicate that 1:2 and 1:1 ordered domains coexist in one grain. The ordering parameter of 1:2 phase decreases with x , yet that of 1:1 phase increases with x . Both increase with soak time. Variations in ordering are discussed in terms of cation occupancy and crystal chemistry. The quality factor increases with x , reaches a maximum, then decreases with x . The dielectric constant increases with x first, and levels off.