基于球差校正扫描透射电镜的快离子导体β-Ag2S中Ag占位表征

基于球差校正扫描透射电镜的快离子导体β-Ag₂S中Ag占位表征

刘　军，陈陆，王　勇^*，张　泽

（浙江大学电子显微镜中心，材料科学与工程学院，硅材料国家重点实验室，浙江 杭州  310027）

摘　要　　目前学界对β-Ag₂S快离子导体中Ag原子占位仍未认识清楚，而这一问题对理解β-Ag₂S的导电机理等特性具有重要意义。本文首次报道了基于球差校正扫描透射电镜（STEM）的β-Ag₂S快离子导体中Ag原子占位表征。沿[100]_β、[-110]_β、[210]_β和[11-1]_β方向的原子级分辨率高角环形暗场（HAADF）像与QSTEM软件高分辨模拟图像对比结果表明Ag原子在6(b)、12(d)和24(h)三类间隙均有分布。原位加热实验结果表明，当温度上升到300℃时Ag原子占位并未发生明显变化。本文为理解β-Ag₂S的结构提供了直接的重要信息。

关键词　　β-Ag₂S；球差校正；STEM；原子占位

中图分类号：O766⁺.1；TG115.21⁺5.3  文献标识码：A   doi:10.3969/j.issn.1000-6281.2019.03.001

Characterization of Ag site occupation in fast ionic conductor β-Ag₂S by spherical-aberration-corrected scanning transmission electron microscopy

LIU Jun，CHEN Lu，WANG Yong^*，ZHANG Ze

（Center of Electron Microscopy and State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou Zhejiang 310027，China）

Abstract    Thesite occupation of Ag atom in β-Ag₂S,which is of great importance for understanding the electrical conduction mechanism and other characteristics of β-Ag₂S, has still not been fully solved. In this paper, the site occupation of Ag atom in β-Ag₂S was characterizedfor the first time using spherical aberration （C_s）-corrected STEM.  The atomic-resolution high-angle annular dark field （HAADF）images along [100]_β, [-110]_β, [210]_β and [11-1]_β zone axes and the simulated HAADF images indicate that Ag atoms occupied 6(b), 12(d) and 24(h) interstices of S framework. In situ heating experiment results show that the site occupation of Ag atoms kept unchanged even when heated to 300 ℃. This work provides new critical information for thoroughly understanding the structure β-Ag₂S.

Keywords  β-Ag₂S；C_s-correction；STEM；atomic site occupation 

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[1] FARADAY M. Experimental researches in electricity. Fourth series.[J]. Philosophical Transactions of the Royal Society of London, 1833, 123: 507-522.

[2] HEBB M H. Electrical conductivity of silver sulfide[J]. The Journal of Chemical Physics，1952，20（1）: 185-190.

[3] RAHLFS P. The cubic high-temperature modifications of sulfides, selenides and tellurides of silver and of univalent copper[J]. ZPhys Chem B, 1936, 31: 157-194.

[4] CAVA R J, REIDINGER F, WUENSCH B J. Single-crystal neutron-diffraction study of AgI between 23° and 300℃[J]. Solid State Commun, 1977, 24（6）: 411-416.

[5] WRIGHT A F, FENDER B E F. The structure of superionic compounds by powder neutron diffraction. I. Cation distribution in α-AgI[J]. Journal of Physics C: Solid State Physics, 1977, 10（13）: 2261-2267.

[6] HOSHINO S, SAKUMA T, FUJII Y. Distribution and anharmonic thermal vibration of cations in α-AgI[J]. Solid State Commun, 1977, 22（12）: 763-765.

[7] HOSHINO S. Crystal structure and phase transition of some metallic halides IV on the anomalous structure of α-AgI[J]. J Phys Soc Jpn, 1957, 12（4）: 315-326.

[8] CAVA R J, REIDINGER F, WUENSCH B J. Single-crystal neutron diffraction study of the fast-ion conductor β-Ag₂S between 186 and 325℃[J]. J Solid State Chem, 1980, 31（1）: 69-80.

[9] 张思瑞, 唐云龙, 朱银莲, 等. 异质界面调控超薄PbTiO₃超薄四方性的研究[J]. 电子显微学报, 2018, 37（4）: 321-325.

[10] 宋述鹏, 王建波, 王仁卉, 等. Al-Co-Ni十次准晶中几种变体结构的HAADF研究[J]. 电子显微学报, 2007, 26（5）: 387-394.

[11] FRUEH A J. The crystallography of silver sulfide, Ag₂S[J]. Zeitschrift für Kristallographie-Crystalline Materials, 1958, 110（1-6）: 136-144.

[12] WANG D S, HAO C H, ZHENG W, et al. Ultralong single-crystalline Ag₂S nanowires: promising candidates for photoswitches and room-temperature oxygen sensors[J]. Adv Mater, 2008, 20（13）: 2628-2632.

[13] 姜超, 陈陆, 刘军,等. VO₂（A）纳米线相变过程的透射电镜原位观察[J]. 电子显微学报, 2017, 36（4）: 301-305.

[14] 陈陆, 刘军, 姜超, 等. VO₂（A）相变过渡态的球差校正扫描透射电镜原位观察[J]. 电子显微学报, 2018, 37（4）: 305-309.

[15] SADANAGA R, SUENO S. X-ray study on the α-β transition of Ag₂S[J]. Mineralogical Journal, 1967, 5（2）: 124-143.