Application of Electron Energy-loss Spectroscopy to BaTiO3 Multi-layer Ceramic Capacitors

doi:10.15541/jim20250021

Abstract

Abstract:

BaTiO₃ multi-layer ceramic capacitors (MLCCs) are meeting the growing performance demands in consumer electronics, aerospace and defense research. Distribution and segregation of elements during complex fabrication process of MLCCs significantly affect the phase composition, microstructures and hence the performance, which necessitates an effective analytical means capable of accurately resolving elements of MLCCs at microscopic scales. Elemental analysis techniques integrated with modern transmission electron microscope (TEM) have unique advantages due to their ultra-high spatial resolution, reaching the sub-angström scale. Among them, energy dispersive X-ray spectroscopy (EDS) provides a simple and fast way for qualitative analysis of metallic elements. However, their limitations, such as low sensitivity for detecting the light element O, and more critically, low energy resolution (~130 eV), which results in the severe overlap of spectral peaks of Ba and Ti elements, hinder accurate quantitative analysis of BaTiO₃. In contrast, electron energy-loss spectroscopy (EELS) possesses ultra-high energy resolution (<1.0 eV), and can provide additional information regarding chemical valence, thus demonstrating enhanced potentials and advantages in the micro-scale elemental analysis of MLCC. In this work, EELS is employed to address the limitation of EDS in distinguishing between Ba and Ti elements due to the overlap of spectral peaks. In addition, EELS reveals that proportion of Ti³⁺ ions is higher in smaller BaTiO₃ grains. Meanwhile, EELS line-scan analysis of individual grains indicates that Ba element diffuses more easily than Ti during sintering process of ceramics. Given its high spatial resolution, EELS offers more accurate and comprehensive information on the elements and valence states, thereby providing potential support for the process improvement and performance optimization of MLCC.

Key words: multi-layer ceramic capacitor, elemental analysis, electron energy-loss spectroscopy, BaTiO₃

CLC Number:

TQ533
TM534

WU Lukang, FU Zhengqian, YU Ziyi, YANG Jun, ZHOU Bin, CHEN Xuefeng, XU Fangfang. Application of Electron Energy-loss Spectroscopy to BaTiO₃ Multi-layer Ceramic Capacitors[J]. Journal of Inorganic Materials, 2025, 40(6): 683-689.

Figures/Tables 8

Fig. 1 (a) Schematic illustration of interaction between high-energy incident electrons and sample within TEM; (b) Principles of EDS and EELS

Fig. 2 (a) Low magnified high angle annular dark field (HAADF) image of MLCC (yellow line is Ni electrode, red line is BaTiO3 dielectric layer); (b) Example area for grain size statistics and average grain size statistics Colorful figures are available on website

Fig. 3 (a) HAADF image of EDS mapping region; (b) EDS spectra (brown peaks marking the overlap of Ba-L and Ti-K peaks); (c) EDS surface distributions of Ba, Ti, O, and Ni Colorful figures are available on website

Fig. 4 EDS and EELS spectra of the same microregion of MLCC samples

Fig. 5 (a) Microregion TEM image of MLCC cross-section sample; (b) EELS spectrum of BaTiO3 single grain identified in (a); (c) Average Ba/Ti atomic ratios of 100 BaTiO3 grains

Fig. 6 HAADF image of BaTiO3 single grain subjected to EELS line analysis and Ba/Ti ratios measured by line scanning (orange line indicating position of the line sweep)

Fig. 7 EELS Ti-L2,3 edge fine structures of BaTiO3 grains with different sizes

Fig. 8 (a) Example HAADF image of dielectric-embedded electrodes; (b-g) EELS spectra for six random embedding positions (indicated by arrows in (a))

References 26

[1]	邓湘云, 李建保, 王晓慧, 等. MLCC的发展趋势及在军用电子设备中的应用. 电子元件与材料, 2006, 25(5): 1.
[2]	KISHI H, MIZUNO Y, CHAZONO H. Base-metal electrode- multilayer ceramic capacitors: past, present and future perspectives. Japanese Journal of Applied Physics, 2003, 42: 1R.
[3]	朱文奕, 张树人, 周晓华, 等. 镍内电极多层陶瓷电容器介质材料的研究. 功能材料, 2000, 31(3): 292.
[4]	杨邦朝, 冯哲圣, 卢云. 多层陶瓷电容器技术现状及未来发展趋势. 电子元件与材料, 2001, 20(6): 17.
[5]	姚立真. 可靠性物理. 北京: 电子工业出版社, 2004.
[6]	CHUN J, HEO J, LEE K, et al. Thermal activation energy on electrical degradation process in BaTiO₃ based multilayer ceramic capacitors for lifetime reliability. Science Reports, 2024, 14: 616.
[7]	SADA T, FUJIKAWA N. Analysis of insulation resistance degradation in Ni-BaTiO₃ multilayer ceramic capacitors under highly accelerated life test. Japanese Journal of Applied Physics, 2017, 56(10S): 10PB04.
[8]	ZHAO C, HUANG Y, WU J. Multifunctional barium titanate ceramics via chemical modification tuning phase structure. InfoMat, 2020, 2(6): 1163.
[9]	ZHANG Q, HE X, SHI J, et al. Atomic-resolution imaging of electrically induced oxygen vacancy migration and phase transformation in SrCoO_2.5-_σ. Nature Communications, 2017, 8: 104.
[10]	AN J S, LEE H S, BYEON P, et al. Unveiling of interstice- occupying dopant segregation at grain boundaries in perovskite oxide dielectrics for a new class of ceramic capacitors. Energy & Environmental Science, 2023, 16(5): 1992.
[11]	王志焜. 用于电子显微镜中的X射线能谱仪. 电子显微学报, 1983(3): 55.
[12]	进藤大辅, 及川哲夫. 材料评价的分析电子显微方法. 北京: 冶金工业出版社, 2001.
[13]	周玉, 武高辉. 材料分析测试技术:材料X射线衍射与电子显微分析. 哈尔滨: 哈尔滨工业大学出版社, 1998.
[14]	王永瑞, 邹骐, 卢党吾. 电子能量损失谱学及其在材料科学中的应用. 物理, 1994, 23(6): 350.
[15]	王乙潜, 杜庆田, 丁艳华, 等. 高分辨率电子能量损失谱在材料科学中的应用. 物理, 2010, 39(12): 839.
[16]	KRIVANEK O L, DELLBY N, HACHTEL J A, et al. Progress in ultrahigh energy resolution EELS. Ultramicroscopy, 2019, 203: 60.
[17]	GLOTER A, DOUIRI A, TENCÉ M, et al. Improving energy resolution of EELS spectra: an alternative to the monochromator solution. Ultramicroscopy, 2003, 96(3): 385.
[18]	LIN I C, HARUTA M, NEMOTO T, et al. Isotropic behavior of oxygen vibrations in PbTiO₃ investigated by Ti L_2,3-edge electron energy-loss spectroscopy. Physical Review B, 2024, 110(3): 035109.
[19]	LEE S B, SIGLE W, RÜHLE M. Investigation of grain boundaries in abnormal grain growth structure of TiO₂-excess BaTiO₃ by TEM and EELS analysis. Acta Materialia, 2002, 50(8): 2151.
[20]	SHAO Y, MAUNDERS C, ROSSOUW D, et al. Quantification of the Ti oxidation state in BaTi_1-_xNb_xO₃ compounds. Ultramicroscopy, 2010, 110(8): 1014.
[21]	YANG G Y, DICKEY E C, RANDALL C A, et al. Oxygen nonstoichiometry and dielectric evolution of BaTiO₃. Part I—improvement of insulation resistance with reoxidation. Journal of Applied Physics, 2004, 96(12): 7492.
[22]	WANG P, HUANG X, LUAN S, et al. Exceptional dielectric performance of MLCCs enabled by defect-engineered BaTiO₃. Journal of Materials Chemistry C, 2024, 12(33): 13131.
[23]	CHANG C Y, WANG R L, HUANG C Y. Effects of Ba/Ti ratio on tetragonality, Curie temperature, and dielectric properties of solid-state-reacted BaTiO₃ powder. Journal of Materials Research, 2012, 27(23): 2937.
[24]	BUGNET M, RADTKE G, WOO S Y, et al. Temperature- dependent high energy-resolution EELS of ferroelectric and paraelectric BaTiO₃ phases. Physical Review B, 2016, 93(2): 020102.
[25]	SAMANTARAY M M, KANEDA K, QU W, et al. Effect of firing rates on electrode morphology and electrical properties of multilayer ceramic capacitors. Journal of the American Ceramic Society, 2012, 95(3): 992.
[26]	YAN Z, GUILLON O, WANG S, et al. Synchrotron X-ray nano- tomography characterization of the sintering of multilayered systems. Applied Physics Letters, 2012, 100(26): 263107.

Application of Electron Energy-loss Spectroscopy to BaTiO₃ Multi-layer Ceramic Capacitors

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