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Structure, Microwave Dielectric Properties and Thermally Stimulated Depolarization Currents of (1 − x )Ba 0.6 Sr 0.4 La 4 Ti 4 O 15 – x Ba 5 Nb 4 O 15 Solid Solutions
Author(s) -
Zhang Xiaohua,
Zhang Jie,
Xie Zhenkun,
Yuan Lixin,
Yue Zhenxing,
Li Longtu
Publication year - 2015
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.13465
Subject(s) - materials science , dielectric , raman spectroscopy , analytical chemistry (journal) , ceramic , perovskite (structure) , crystal structure , x ray crystallography , relaxation (psychology) , diffraction , sintering , mineralogy , crystallography , composite material , optics , chemistry , psychology , social psychology , physics , optoelectronics , chromatography
(1 − x )Ba 0.6 Sr 0.4 La 4 Ti 4 O 15 – x Ba 5 Nb 4 O 15 ( x = 0.05, 0.1, 0.15 and 0.2, BSLT–BN) ceramic samples were prepared by co‐firing the mixtures of Ba 0.6 Sr 0.4 La 4 Ti 4 O 15 and Ba 5 Nb 4 O 15 powders. Crystal structure, microwave dielectric properties and thermally stimulated depolarization currents (TSDC) of the BSLT–BN series ceramics were investigated. X‐ray diffraction patterns reveal that all the samples exhibit a hexagonal perovskite structure, which implies that the BSLT–BN mixtures form solid solutions. With increasing Ba 5 Nb 4 O 15 content, the diffraction peaks shift to low angles and the sintering temperature of BSLT–BN decreases. Raman spectra analysis reveals the shifting and splitting of the vibration modes. The microwave dielectric properties of the well‐sintered (1 − x )BSLT– x BN ceramics vary with Ba 5 Nb 4 O 15 content. The dielectric permittivity of the ceramics exhibits a slight decreasing trend. The quality factor varies in the range of 45 000–11 200 GHz, whereas near‐zero temperature coefficients of the resonant frequency may be achieved by changing the Ba 5 Nb 4 O 15 content. TSDC was utilized to explore the extrinsic loss mechanism associated with defects. TSDC relaxation peaks are mainly generated by oxygen vacancies, and the Ba 5 Nb 4 O 15 content has a significant influence on the TSDC spectra.