无机材料学报 ›› 2021, Vol. 36 ›› Issue (1): 95-100.DOI: 10.15541/jim20190564

所属专题: 副主编黄庆研究员专辑

• 研究快报 • 上一篇    下一篇

AlF3掺杂氧化铝陶瓷的高灵敏辐照诱导相分离行为

申璐1,汪德文2,黄荣3,都时禹1,黄庆1()   

  1. 1. 中国科学院 宁波材料技术与工程研究所, 宁波 315201
    2. 中国科学院 上海硅酸盐研究所, 上海200050
    3. 华东师范大学 电子科学系, 极化材料与器件教育部重点实验室, 上海 200062
  • 收稿日期:2020-11-04 修回日期:2020-02-20 出版日期:2021-01-20 发布日期:2020-07-21
  • 作者简介:申璐(1988-), 男, 博士. E-mail: shenlu@nimte.ac.cn

Electron Irradiation Induced Phase-separation Behavior in AlF3 Doped Alumina Ceramic with Superior Sensitivity

SHEN Lu1,WANG Dewen2,HUANG Rong3,DU Shiyu1,HUANG Qing1()   

  1. 1. Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
    2. Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
    3. Key Laboratory of Polar Materials and Devices (MOE), Department of Electronics, East China Normal University, Shanghai 200062, China
  • Received:2020-11-04 Revised:2020-02-20 Online:2021-01-20 Published:2020-07-21
  • About author:SHEN Lu(1988-), male, PhD. E-mail: shenlu@nimte.ac.cn
  • Supported by:
    National Natural Science Foundation of China(51172248);Zhejiang Provincial Natural Science Foundation of China(R12E020005)

摘要:

放电等离子体烧结的AlF3掺杂氧化铝陶瓷在透射电镜(TEM)常规观察条件下发现了一种电子辐照诱导快速相分离行为。在透射电镜的电子辐照下, 球形纳米晶Al颗粒在几秒钟内从原始氧化铝晶粒表面析出。高分辨TEM观察结合衍射花样分析发现原始的F掺杂氧化铝晶粒表面为高度缺陷态, 电子辐照后, 随着Al纳米颗粒析出, 氧化铝晶粒表面的缺陷消失。通过对掺杂过程缺陷反应及氧化铝阳离子亚晶格的深入分析, 提出了一种缺陷辅助间隙原子偏析机理来解释这一现象。即掺杂F离子首先占据氧空位的同时Al离子占据间隙位, 当氧空位被全部占据时, F和Al离子同时占据基体八面体间隙位, 并形成了亚稳定的掺杂态。在氧化铝基体1/3 [11ˉ00]不全位错的作用下, 畸变的阳离子亚晶格产生双聚八面体间隙位。当这些双聚八面体空位被外来Al离子占据时, 正如高分辨图像所观察的, 形成了包含有三个原子层左右的堆垛层错。同时, 沿着层错偏聚在双聚八面体位的掺杂Al离子扮演了析出物早期的角色, 在电子辐照下随着F离子的烧蚀, 不稳定的偏聚Al离子析出成为纳米颗粒并伴随着基体氧化铝的晶格重构。

关键词: AlF3, Al2O3, TEM, 电子辐照, 相分离

Abstract:

An electron irradiation induced fast phase-separation behavior was observed under convention Transmission electron microscopy (TEM) observation of spark plasma sintered AlF3 doped alumina ceramic. Spherical nanocrystalline Al precipitates separated out from original alumina grain surface within several seconds under transmission electron microscopy electron irradiation. By high resolution TEM observation combined with diffraction patterns analysis, it was found that the original alumina grain surface was in highly defected state. After electron irradiation under TEM, the defects on original alumina surface vanished accompanied by the precipitation of nanocrystalline Al particles. By thoroughly analysis of the defect reaction during doping process and the feature of cation sub-lattice of alumina, a defect assisted interstitial atom segregation mechanism was proposed to explain this behavior. According to this mechanism, doped F ions first occupied oxygen vacancy sites with corresponding Al ions at intrinsic interstitial sites. After oxygen vacancies being fully occupied, both F and Al ions tended to settle down at intrinsic octahedron interstitial sites, which resulted in a metastable doping state. Under the act of 1/3 [11ˉ00] partial dislocation of alumina matrix, distorted cation sub-lattice generated double aggregated vacant octahedron sites. When these doublets vacant octahedron sites were occupied by foreign Al ions, stacking faults composed of about three sequences were generated as that observed in high resolution TEM. Meanwhile, the segregated doping Al ions at double aggregated octahedron sites along the stacking faults worked as early stage precipitations. Under electron irradiation, with the ablation of F ions, the unstable segregated Al ions separated out as nano precipitation with the reconstruction of alumina lattice.

Key words: AlF3, Al2O3, TEM, electron irradiation, phase-separation

中图分类号: