Structure, impedance and conduction mechanisms of tape-casting (Bi0.44Nd0.01Sr0.02Ca0.02)Na0.5TiO2.965 ceramic film
Structure, impedance and conduction mechanisms of tape-casting (Bi0.44Nd0.01Sr0.02Ca0.02)Na0.5TiO2.965 ceramic film
复制标题
DOI：
10.1016/j.ceramint.2023.01.047
复制
发表时间：
2023-01
影响因子：
5.2
通讯作者：
C. Ye;Yunxia Zhao;Yanrui Li;Xin Zhao;Min Li;Jing Shi;Xiao Liu
中科院分区：
文献类型：
--
作者：
C. Ye;Yunxia Zhao;Yanrui Li;Xin Zhao;Min Li;Jing Shi;Xiao Liu
Bi_（0.5）Na_（0.5）TiO_3（BNT）基配合物是近年来发展起来的一种新型压电材料。虽然BNT基材料的性能改性研究已经深入，但由于其对导电性能的特殊敏感性，制备工艺对材料结构和导电机理的影响尚未得到应有的重视。本文采用流延法和传统固相反应法制备了（Bi 0.44 Nd 0.01 Sr 0.02 Ca 0.02）Na 0.5TiO 2.965（BNSCNT）陶瓷。尽管由SR制备的BNSCNT陶瓷具有菱面体畸变的纯钙钛矿相，但可以确定用于TC的金红石二氧化钛相。交流阻抗谱揭示了一个明显的整体响应与可观的氧化物离子导电能力SR，而从每个物理起源的贡献变得模糊，由于叠加在Nyquist图TC。结合活化能推导出的热依赖性的电导率，这是显着小于介电BNT，占主导地位的离子导电性质与不可忽略的电子贡献提出。采用直流偏置场和气氛，揭示了晶界和电极/界面响应，以及它们在中频范围内的导电机制。场致反向变化是公认的缺陷团簇的解离负责SR，而捕获的样品表面和第二相的导电电子将发挥关键作用TC，在确定其阻抗。这项工作提出了制备路线对BNT基氧化物离子导电材料的结构和导电机制的重要性。
Bi0.5Na0.5TiO3(BNT)-based complexes, one of the most promising piezoelectric materials, have been recently raised as potential ionic conductors. Although the property modification of BNT-based materials was studied intensively, the influence of the preparation process on the structure and conduction mechanism has not received the attention it deserves since its particular sensitivity to the conductive performance. Herein, (Bi0.44Nd0.01Sr0.02Ca0.02)Na0.5TiO2.965(BNSCNT) ceramics were prepared by tape-casting (TC) and conventional solid-state reaction (SR) method, respectively. Despite the pure perovskite phase with rhombohedral distortion of BNSCNT ceramics prepared by SR, the rutile titanium dioxide phase can be identified for TC. The ac impedance spectra reveal a discernible bulk response with appreciable oxide ion conductive capacity in SR, while the contribution from each physical origin becomes obscure due to the superposition in the Nyquist plots of TC. Combined with the activation energy deduced from the thermally dependent conductivity, which is significantly less than the dielectric BNTs, the dominated ionic conductive nature with non-negligible electron contribution is proposed. The grain boundary and electrodes/interfaces response, and their conduction mechanism in the intermediate frequencies range are disclosed by employing the dc bias field and atmospheres. The field-induced inverse variation is recognized of which the dissociation of defect clusters is responsible for SR, whereas the trapping of conduction electrons on the sample surface and the second phase will play the key role for TC, in determining their impedance. This work raises the great importance of the preparation route on the structure and conduction mechanisms of BNT-based oxide ionic conductive materials.