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Author(s): |
Chang-jiang Xiao, School of Material Science and Technology, Henan University of Technology, Zhengzhou, China, 450007
Zheng-xin Li, School of Material Science and Technology, Henan University of Technology, Zhengzhou, China, 450007
Xiang-rong Deng, School of Material Science and Technology, Henan University of Technology, Zhengzhou, China, 450007
Xue-feng Yang, School of Material Science and Technology, Henan University of Technology, Zhengzhou, China, 450007
Dong-dong Song, School of Material Science and Technology, Henan University of Technology, Zhengzhou, China, 450007 |
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Abstract: |
10 nm raw BaTiO3 powder was fabricated by ultra-high pressure sintering at 6GPa. The grain size of BaTiO3 ceramics was calculated to be about 30 nm. During ultra-high pressure sintering, oxygen vacancies were produced owing to strongly reducing atmosphere. The paper investigated the effect of oxygen vacancies of nanocrystalline BaTiO3 ceramics on its ferroelectric properties. The results showed that, for as-prepared 30 nm BaTiO3 ceramics, the dielectric constant was 3175 at Curie temperature and the dielectric losses were more than 1.1 at temperatures ranging from 80 to 150 ℃；moreover there exist no full hysteresis loop; After annealing in O2 atmosphere at 600 °C for 8 h, dielectric constant decreased to1920 at Curie temperature whereas the dielectric losses were less than 0.15；full hysteresis loop could be shaped at different electric field. Furthermore, F+ centers were formed because oxygen vacancies caught electrons, therefore the color of nanocrystalline BaTiO3 ceramics became black; on the contrary, the post-annealed 30 nm BaTiO3 ceramics was white.
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