Direct Control of Defects on Positron Lifetimes and Dielectric Constant of Microwave Ceramics
Direct Control of Defects on Positron Lifetimes and Dielectric Constant of Microwave Ceramics
复制标题
缺陷对微波陶瓷正电子寿命和介电常数的直接控制
DOI：
10.1111/jace.12354
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发表时间：
2013-08
影响因子：
3.9
通讯作者：
Deng, Wen
中科院分区：
文献类型：
--
作者：
Tang, Yu;Zhang, Yi;Du, Piyi;Deng, Wen
在正电子湮没技术(PAT)中，完整地发现缺陷与正电子寿命之间的关系，清楚地揭示缺陷对通用微波陶瓷介电常数的影响具有重要意义。本文采用固相反应法制备了具有非化学计量缺陷的−_xTixO_6−_x(0~≤_x·≤_(0.5))介电陶瓷。用PAT可以准确地显示出所制备陶瓷中的所有气孔和缺陷，是一种方便的方法。正电子湮没寿命谱(PALS)中τ-3和τ-2的正电子寿命取决于两种与o-Ps原子和俘获正电子湮没位置相关的气孔，而τ-1的正电子寿命明显分离为τb和τt，这两种气孔与体系中的体结构和负电荷缺陷有关。在10 GHz频段，随着x从0增加到0.5，微波陶瓷材料的介电常数从26增加到49，证实了−‘的负电荷缺陷通过阳离子振荡直接控制着−’的介电常数。
It is of great importance to discover completely the correlation between the defects and positron lifetimes in positron annihilation technology (PAT) and reveal clearly the effect of defects on the dielectric constant of universal microwave ceramics. In this work, ZnNb2−xTixO6−x (0 ≤ x ≤ 0.5) dielectric ceramics with nonstoichiometric defects were prepared by solid-state reaction. All the pores and defects in as-prepared ceramics were accurately revealed by PAT as a convenient way. The positron lifetimes of τ3 and τ2 in positron annihilation lifetime spectra (PALS) were dependent on two kinds of pores correlated with where o-Ps atoms and trapping positron annihilated in, whereas τ1 could be separated evidently into τb and τt which are related to bulk structure and negatively charged defects in the system. The dielectric constant of microwave ceramics ZnNb2−xTixO6−x, which increases from 26 to 49 with x increasing from 0 to 0.5 at 10 GHz, is confirmed to be directly controlled by the negatively charged defect of TiNb ' through cation rattling.
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影响因子：
4
作者：
Jiquan Huang;Yongge Cao;M. Hong;P. Du
通讯作者：
Jiquan Huang;Yongge Cao;M. Hong;P. Du
影响因子：
3.2
作者：
SHANNON, RD
通讯作者：
SHANNON, RD
影响因子：
1.7
作者：
Y. Zhang;Zhenxing Yue;Z. Gui;L. Li
通讯作者：
Y. Zhang;Zhenxing Yue;Z. Gui;L. Li
影响因子：
3.2
作者：
Dong Wang;Z. Q. Chen;D. D. Wang-D.;N. Qi;J. Gong;C. Cao;Z. Tang
通讯作者：
Dong Wang;Z. Q. Chen;D. D. Wang-D.;N. Qi;J. Gong;C. Cao;Z. Tang
影响因子：
--
作者：
S. Roberts
通讯作者：
S. Roberts