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High‐permittivity and conduction mechanism of La‐doped Ba 0.67 Sr 0.33 TiO 3 ceramics
Author(s) -
Xu Jing,
Liu HanXing,
He Bo,
Hao Hua,
Cao MingHe
Publication year - 2012
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201200001
Subject(s) - materials science , permittivity , dielectric , doping , ceramic , microstructure , curie temperature , dielectric loss , scanning electron microscope , analytical chemistry (journal) , condensed matter physics , composite material , optoelectronics , chemistry , physics , ferromagnetism , chromatography
High permittivity La‐doped Ba 0.67 Sr 0.33 TiO 3 ceramics (BSTL) with cubic perovskite structure, i.e., Ba x Sr 1− x TiO 3 (BST) + x at.% La, where x = 0–1, were prepared by conventional ceramic processing techniques. Dielectric characteristics, X‐ray diffraction, scanning electron microscopy (SEM), and J – V (leakage current density–voltage) behaviors were measured. Doping with the La in the BST host lattice resulted in a large‐grained (1–3 µm) and fine‐grained (0.3–1 µm) microstructure, marked raising, and broadening of the Curie peak. The temperature of dielectric peak ( T m ) at 10 kHz decreased rapidly with a doping concentration of <0.7 at.% La. By means of doping with La, high dielectric constant ceramics (BSTL: 0.2 ≤ x ≤ 0.7) with permittivity at room temperature ( ε RT ) > 110 000 at 10 kHz have been achieved. The plots of leakage current density versus voltage show the different electrical conduction mechanism in different voltage ranges.