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Defect chemistry of A site nonstoichiometry and the resulting dielectric behaviors in Sr x Ti 0.985 (Nb 2/3 Zn 1/3 ) 0.015 O 3 ceramics
Author(s) -
Pan Wengao,
Cao Minghe,
Hao Hua,
Yao Zhonghua,
Yu Zhiyong,
Liu Hanxing
Publication year - 2020
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.17345
Subject(s) - dielectric , vacancy defect , materials science , crystallographic defect , polarization (electrochemistry) , density functional theory , ceramic , electronic structure , oxygen , condensed matter physics , chemical physics , analytical chemistry (journal) , mineralogy , crystallography , chemistry , metallurgy , computational chemistry , optoelectronics , physics , organic chemistry , chromatography
Abstract Defect chemistry of Sr site nonstoichiometry in Sr x Ti 0.985 (Nb 2/3 Zn 1/3 ) 0.015 O 3 ceramics and the resulting effects on the structure and dielectric behavior are systematically investigated by experiment and density functional theory (DFT) methods. The results indicate that, appropriate Sr deficiency benefits the dielectric properties and grain growth due to the creation of Sr vacancy. While Sr excess deteriorates the dielectric properties and inhibits the grain growth by forming a Ruddlesden‐Popper structure. In Sr‐deficient sample, more point defects arise and aggregate into defect clusters, resulting in great changes in local structures and the enhancement of dielectric properties. The Sr vacancy benefits the generation of oxygen vacancy, thus facilitating the localization of electrons and the decrease in dielectric loss. Besides, the electronic polarization and structural polarization are also improved by Sr vacancy and the resultant oxygen vacancy, leading to the further enhanced dielectric properties. These findings may facilitate the development of defect engineering towards novel multifunctional electronic materials.