具有高介電常數特性的鈦酸鋇是積層陶瓷電容中常用的介電陶瓷材料，一般需要1350℃左右高溫燒結才能夠達到緻密化，而在此高溫下內電極導電金屬易發生劇烈收縮而產生裂縫，造成電容值降低。適當添加玻璃作為助燒結劑來降低燒結溫度是必要的步驟，Li2O-B2O3-SiO2 (LBS)玻璃具有低熔融點的特性，可作為良好的助燒結劑。本研究以開發LBS玻璃的製程為目標，利用濕式化學法製備LBS膠體溶液，分析在LBS對鈦酸鋇陶瓷體之助燒結效果以及介電性質的表現。在固定LBS成分組成下 (40Li2O-20B2O3-40SiO2 ,L2S2)探討螯合劑對玻璃特性的差異，研究發現添加檸檬酸作為螯合劑能使鋰離子置於硼矽網絡結構內，加上多官能基的乙二醇聚合法，改善LBS的成分分布均勻性，形成的LBS玻璃具有較低的玻璃軟化溫度與熔融溫度；具有較低熔點的LBS玻璃添加量從1 wt.%降至0.33 wt.%後可避免鈦酸鋇陶瓷體過度燒結的現象。將LBS中Li2O與B2O3的占比下降、SiO2占比提高 (25Li2O-12.5B2O3-62.5SiO2 ,L2S5)後，L2S5的玻璃軟化溫度與熔融溫度有提高的趨勢，因此L2S5/BT燒結緻00密溫度較L2S2/BT高50℃，但由於L2S5的Li2O占比下降，pinning effect較小，使殼層 (shell)較厚，進而得到較L2S2/BT低的介電損耗與較高的絕緣電阻率。而LBS/BT的燒結溫度不僅比SiO2/BT低150-200℃，電容值對溫度的變化率也有符合X7R的規範。

Barium titanate (BT) is a widely used material for multi-layer ceramic capacitors. BT requires a high sintering temperature of 1350°C to achieve densification. At this high sintering temperature, the internal electrodes would shrinkage and crack, which results in a decreasing in capacitance value. To address this issue, the addition of glass as a sintering aid is necessary to lower the BT sintering temperature. A study investigated the impact of Li2O-B2O3-SiO2 (LBS) glass in BT ceramic. The influence of chelating agents on the characteristics of the LBS glass is investigated under a fixed LBS composition (40Li2O-20B2O3-40SiO2, L2S2). By using citric acid as a chelating agent, lithium ions easier incorporated into the glass structure. The ethylene glycol polymerization method improves the uniform distribution of LBS composition, resulting in lower glass softening and melting points. Additionally, over-firing of the BT ceramic body is effectively prevented by reducing the addition of low melting LBS glass (CE-L2S2) from 1 wt.% to 0.33 wt.%. The glass softening and melting points of 25Li2O-12.5B2O3-62.5SiO2 (L2S5) are increased by reducing the proportion of Li2O and B2O3 while increasing the proportion of SiO2 in LBS. As the result, the sintering temperature of L2S5/BT is higher than L2S2/BT. The pinning effect becomes less significant by decreasing the proportion of Li2O in L2S5, which results in a thicker shell structure. Consequently, L2S5/BT demonstrates lower dielectric loss and higher resistivity compared to L2S2/BT. Moreover, the sintering temperature of LBS/BT is not only 150-200°C lower than SiO2/BT but also the temperature coefficient of capacitance meets the X7R specification.

[1] Rase, D.E. and R. Roy, "Phase Equilibria in the System BaO-TiO2," Journal of the American Ceramic Society, vol. 38, pp. 102-113, (2006).
[2] Hsiao-Lin, W., "Structure and dielectric properties of perovskite–Barium Titanate (BaTiO3)," Submitted in Partial Fulfillment of Course Requirement for MatE, vol. 115, pp. 3-9, (2002).
[3] Shirane, G., F. Jona, and R. Pepinsky, "Some aspects of ferroelectricity," Proceedings of the IRE, vol. 43, pp. 1738-1793, (1955).
[4] Lee, W., C. Su, Y. Lee, S. Lin, and T. Yang, "Effects of dopant on the dielectric properties of CaZrO3 ceramic sintered in a reducing atmosphere," Japanese Journal of Applied Physics, vol. 45, pp. 5853, (2006).
[5] Burn, I., "Mn-doped polycrystalline BaTiO3," Journal of Materials Science, vol. 14, pp. 2453-2458, (1979).
[6] Tsur, Y., T.D. Dunbar, and C.A. Randall, "Crystal and defect chemistry of rare earth cations in BaTiO3," Journal of Electroceramics, vol. 7, pp. 25-34, (2001).
[7] Hillert, M., "On the theory of normal and abnormal grain growth," Acta metallurgica, vol. 13, pp. 227-238, (1965).
[8] Arlt, G., D. Hennings, and G. De With, "Dielectric properties of fine‐grained barium titanate ceramics," Journal of Applied Physics, vol. 58, pp. 1619-1625, (1985).
[9] Matsuo, Y. and H. Sasaki, "Exaggerated Grain Growth in Liquid‐Phase Sintering of BaTiO3," Journal of the American Ceramic Society, vol. 54, pp. 471-471, (1971).
[10] Xue, L.A., "Thermodynamic benefit of abnormal grain growth in pore elimination during sintering," Journal of the American Ceramic Society, vol. 72, pp. 1536-1537, (1989).
[11] Demartin, M., C. Hérard, C. Carry, and J. Lemaître, "Dedensification and anomalous grain growth during sintering of undoped barium titanate," Journal of the American Ceramic Society, vol. 80, pp. 1079-1084, (1997).
[12] Du, M., Y. Li, Y. Yuan, S. Zhang, and B. Tang, "A Novel Approach to BaTiO3-based X8R Ceramics by Calcium Borosilicate Glass Ceramic Doping," Journal of Electronic Materials, vol. 36, pp. 1389-1394, (2007).
[13] Jeon, H.-P., S.-K. Lee, S.-W. Kim, and D.-K. Choi, "Effects of BaO–B2O3–SiO2 glass additive on densification and dielectric properties of BaTiO3 ceramics," Materials Chemistry and Physics, vol. 94, pp. 185-189, (2005).
[14] Yang, W.-G., B.-P. Zhang, N. Ma, and L. Zhao, "High piezoelectric properties of BaTiO3–xLiF ceramics sintered at low temperatures," Journal of the European Ceramic Society, vol. 32, pp. 899-904, (2012).
[15] Lee, H.-Y., J.-S. Kim, N.-M. Hwang, and D.-Y. Kim, "Effect of sintering temperature on the secondary abnormal grain growth of BaTiO3," Journal of the European Ceramic Society, vol. 20, pp. 731-737, (2000).
[16] German, R.M., P. Suri, and S.J. Park, "Review: liquid phase sintering," Journal of Materials Science, vol. 44, pp. 1-39, (2009).
[17] Esposito, S., ""Traditional" Sol-Gel Chemistry as a Powerful Tool for the Preparation of Supported Metal and Metal Oxide Catalysts," Materials (Basel), vol. 12, pp. (2019).
[18] Brinker, C.J. and G.W. Scherer, "Sol→ gel→ glass: I. Gelation and gel structure," Journal of Non-Crystalline Solids, vol. 70, pp. 301-322, (1985).
[19] Danks, A.E., S.R. Hall, and Z. Schnepp, "The evolution of ‘sol–gel’ chemistry as a technique for materials synthesis," Materials Horizons, vol. 3, pp. 91-112, (2016).
[20] Dimesso, L., "Pechini processes: an alternate approach of the sol–gel method, preparation, properties, and applications," Handbook of Sol-Gel Science and Technology, vol. 2, pp. 1-22, (2016).
[21] Zachariasen, W.H., "The atomic arrangement in glass," Journal of the American Chemical Society, vol. 54, pp. 3841-3851, (1932).
[22] Deshmukh, K., T. Kovářík, T. Křenek, D. Docheva, T. Stich, and J. Pola, "Recent advances and future perspectives of sol–gel derived porous bioactive glasses: a review," RSC advances, vol. 10, pp. 33782-33835, (2020).
[23] Barlet, M., A. Kerrache, J.-M. Delaye, and C.L. Rountree, "SiO2–Na2O–B2O3 density: A comparison of experiments, simulations, and theory," Journal of Non-Crystalline Solids, vol. 382, pp. 32-44, (2013).
[24] Liu, F., X. Guo, and G. Yang, "Crystallization of gels in the SiO2-ZrO2-B2O3 system," Journal of Materials Science, vol. 36, pp. 579-585, (2001).
[25] Zhou, F., D. Xu, M. Shi, and Y. Bi, "Investigation on microstructure and its transformation mechanisms of B2O3-SiO2-Al2O3-CaO brazing flux system," High Temperature Materials and Processes, vol. 39, pp. 88-95, (2020).
[26] Grandjean, A., M. Malki, V. Montouillout, F. Debruycker, and D. Massiot, "Electrical conductivity and 11B NMR studies of sodium borosilicate glasses," Journal of Non-Crystalline Solids, vol. 354, pp. 1664-1670, (2008).
[27] Muralidharan, P., M. Venkateswarlu, and N. Satyanarayana, "Acid catalyst concentration effect on structure and ion relaxation studies of Li2O–P2O5–B2O3–SiO2 glasses synthesized by sol–gel process," Journal of Non-Crystalline Solids, vol. 351, pp. 583-594, (2005).
[28] Michel, F., L. Cormier, P. Lombard, B. Beuneu, L. Galoisy, and G. Calas, "Mechanisms of boron coordination change between borosilicate glasses and melts," Journal of Non-crystalline Solids, vol. 379, pp. 169-176, (2013).
[29] Samee, M.A., A. Edukondalu, S.K. Ahmmad, S.M. Taqiullah, and S. Rahman, "Mixed-Alkali Effect in Li2O–Na2O–K2O–B2O3 Glasses: Infrared and Optical Absorption Studies," Journal of Electronic Materials, vol. 42, pp. 2516-2524, (2013).
[30] Shih, Y.-T. and J.-H. Jean, "Low-fire processing of microwave (Ca1− xSrx)(Zr1− yMny) O3 dielectric with Li2O-B2O3-SiO2 glass in H2/N2," Ceramics International, vol. 43, pp. S306-S311, (2017).
[31] Li, Y.Q., H.X. Liu, Z.H. Yao, J. Xu, Y.J. Cui, M.H. Cao, H. Hao, and Z.Y. Yu, "The Effect of ZnO–B2O3–SiO2Additive on Sintering and Dielectric Properties of Ba0.3Sr0.7TiO3Ceramics," Ferroelectrics, vol. 403, pp. 45-53, (2010).
[32] Prakash, B.S. and K. Varma, "Effect of the addition of B2O3 and BaO–B2O3–SiO2 glasses on the microstructure and dielectric properties of giant dielectric constant material CaCu3Ti4O12," Journal of Solid State Chemistry, vol. 180, pp. 1918-1927, (2007).
[33] Wu, Z., H. Liu, M. Cao, Z. Shen, Z. Yao, H. Hao, and D. Luo, "Effect of BaO-Al2O3-B2O3-SiO2 glass additive on densification and dielectric properties of Ba0. 3Sr0. 7TiO3 ceramics," Journal of the Ceramic Society of Japan, vol. 116, pp. 345-349, (2008).
[34] Shen, Z., H. Liu, Z. Wu, Z. Yao, M. Cao, and D. Luo, "Preparation and dielectric properties of Sr (Ti0. 95Zr0. 05) O3 ceramics doped with CaOTiO2SiO2 (CTS)," Materials Science and Engineering: B, vol. 136, pp. 11-14, (2007).
[35] Shin, H.K., H. Shin, S.Y. Cho, and K.S. Hong, "Phase evolution and dielectric properties of MgTiO3–CaTiO3‐based ceramic sintered with lithium borosilicate glass for application to low temperature co‐fired ceramics," Journal of the American Ceramic Society, vol. 88, pp. 2461-2465, (2005).
[36] Xiang, W. and J. Zhong, Borosilicates Obtained by Sol-Gel Method, in Handbook of Sol-Gel Science and Technology. 2018. p. 621-665.
[37] Basin, A.S., A.B. Kaplun, A.B. Meshalkin, and N.F. Uvarov, "The LiCl-KCl binary system," Russian Journal of Inorganic Chemistry, vol. 53, pp. 1509-1511, (2008).
[38] Galeener, F.L., "Band limits and the vibrational spectra of tetrahedral glasses," Physical Review B, vol. 19, pp. 4292-4297, (1979).
[39] Aguiar, H., J. Serra, P. González, and B. León, "Structural study of sol–gel silicate glasses by IR and Raman spectroscopies," Journal of Non-Crystalline Solids, vol. 355, pp. 475-480, (2009).
[40] Terry, R.J., C.D. McMillen, X. Chen, Y. Wen, L. Zhu, G. Chumanov, and J.W. Kolis, "Hydrothermal single crystal growth and second harmonic generation of Li2SiO3, Li2GeO3 and Li2Si2O5," Journal of Crystal Growth, vol. 493, pp. 58-64, (2018).
[41] Richet, P., B.O. Mysen, and D. Andrault, "Melting and premelting of silicates: Raman spectroscopy and X-ray diffraction of Li2-SiO3 and Na2-SiO 3," Physics and Chemistry of Minerals, vol. 23, pp. 157-172, (1996).
[42] González, P., J. Serra, S. Liste, S. Chiussi, B. León, and M. Pérez-Amor, "Raman spectroscopic study of bioactive silica based glasses," Journal of Non-Crystalline Solids, vol. 320, pp. 92-99, (2003).
[43] Winterstein-Beckmann, A., D. Möncke, D. Palles, E.I. Kamitsos, and L. Wondraczek, "A Raman-spectroscopic study of indentation-induced structural changes in technical alkali-borosilicate glasses with varying silicate network connectivity," Journal of Non-Crystalline Solids, vol. 405, pp. 196-206, (2014).
[44] Mysen, B.O. and J.D. Frantz, "Raman spectroscopy of silicate melts at magmatic temperatures: Na2O-SiO2, K2O-SiO2 and Li2O-SiO2 binary compositions in the temperature range 25–1475 C," Chemical Geology, vol. 96, pp. 321-332, (1992).
[45] Fukumi, K., J. Hayakawa, and T. Komiyama, "Intensity of Raman band in silicate glasses," Journal of Non-Crystalline Solids, vol. 119, pp. 297-302, (1990).
[46] Manara, D., A. Grandjean, and D.R. Neuville, "Advances in understanding the structure of borosilicate glasses: A Raman spectroscopy study," American Mineralogist, vol. 94, pp. 777-784, (2009).
[47] Ortiz-Landeros, J., C. Gomez-Yanez, and H. Pfeiffer, "Surfactant-assisted hydrothermal crystallization of nanostructured lithium metasilicate (Li2SiO3) hollow spheres: II—Textural analysis and CO2–H2O sorption evaluation," Journal of Solid State Chemistry, vol. 184, pp. 2257-2262, (2011).
[48] Pathak, M.S., N.O. Gopal, N. Singh, M. Mohapatra, J.L. Rao, J.-K. Lee, and V. Singh, "Synthesis and investigations on correlation between EPR and optical properties of Fe doped Li2SiO3," Journal of Non-Crystalline Solids, vol. 500, pp. 266-271, (2018).
[49] Kaur, R., S. Singh, and O.P. Pandey, "Structural variation in gamma ray irradiated PbO–Na2O–B2O3–SiO2 glasses," Solid State Communications, vol. 188, pp. 40-44, (2014).
[50] Fernandes, J.S., P. Gentile, R. Moorehead, A. Crawford, C.A. Miller, R.A. Pires, P.V. Hatton, and R.L. Reis, "Design and Properties of Novel Substituted Borosilicate Bioactive Glasses and Their Glass-Ceramic Derivatives," Cryst. Growth Des., vol. 16, pp. 3731-3740, (2016).
[51] Muralidharan, P., "Sol–gel synthesis, structural and ion transport studies of lithium borosilicate glasses," Solid State Ionics, vol. 166, pp. 27-38, (2004).
[52] Kracek, F.C., "Phase equilibrium relations in the system, Na2SiO3-Li2SiO3-SiO2," Journal of the American Chemical Society, vol. 61, pp. 2863-2877, (1939).
[53] Duran, P., J. Tartaj, and C. Moure, "Sintering behaviour and microstructural evolution of agglomerated spherical particles of high-purity barium titanate," Ceramics International, vol. 29, pp. 419-425, (2003).
[54] Kim, C.-H., K.-S. Oh, and Y.-K. Paek, "Microstructure Evolution and Dielectric Characteristics of CaCu3Ti4O12Ceramics with Sn-Substitution," Journal of the Korean Ceramic Society, vol. 50, pp. 87-91, (2013).
[55] Goncharenko, A., V. Lozovski, and E. Venger, "Lichtenecker's equation: applicability and limitations," Optics Communications, vol. 174, pp. 19-32, (2000).
[56] Luan, W., L. Gao, and J. Guo, "Size effect on dielectric properties of fine-grained BaTiO3 ceramics," Ceramics International, vol. 25, pp. 727-729, (1999).
[57] Lee, Y.-c., W.-h. Lu, S.-h. Wang, and C.-w. Lin, "Effect of SiO2 addition on the dielectric properties and microstructure of BaTiO3-based ceramics in reducing sintering," International Journal of Minerals, Metallurgy and Materials, vol. 16, pp. 124-127, (2009).
[58] Lou, Q., X. Shi, X. Ruan, J. Zeng, Z. Man, L. Zheng, C.H. Park, and G. Li, "Ferroelectric properties of Li‐doped BaTiO3 ceramics," Journal of the American Ceramic Society, vol. 101, pp. 3597-3604, (2018).
[59] Solomatov, V., R. El-Khozondar, and V. Tikare, "Grain size in the lower mantle: constraints from numerical modeling of grain growth in two-phase systems," Physics of the Earth and planetary interiors, vol. 129, pp. 265-282, (2002).
[60] Ma, N., B.-P. Zhang, and W.-G. Yang, "Low-temperature sintering of Li2O-doped BaTiO3 lead-free piezoelectric ceramics," Journal of Electroceramics, vol. 28, pp. 275-280, (2012).
[61] Kracek, F., "The binary system Li2O–SiO2," The Journal of Physical Chemistry, vol. 34, pp. 2641-2650, (2002).
[62] Lubauer, J., K. Hurle, M.R. Cicconi, A. Petschelt, H. Peterlik, U. Lohbauer, and R. Belli, "Toughening by revitrification of Li2SiO3 crystals in Obsidian® dental glass-ceramic," Journal of the Mechanical Behavior of Biomedical Materials, vol. 124, pp. 104739, (2021).
[63] Möncke, D., R. Ehrt, D. Palles, I. Efthimiopoulos, E.I. Kamitsos, and M. Johannes, "A multi technique study of a new lithium disilicate glass-ceramic spray-coated on ZrO2 substrate for dental restoration," Biomedical Glasses, vol. 3, pp. (2017).
[64] Belli, R., M. Wendler, M.R. Cicconi, D. de Ligny, A. Petschelt, K. Werbach, H. Peterlik, and U. Lohbauer, "Fracture anisotropy in texturized lithium disilicate glass-ceramics," Journal of Non-Crystalline Solids, vol. 481, pp. 457-469, (2018).
[65] Sreenivasan, H., P. Kinnunen, E. Adesanya, M. Patanen, A.M. Kantola, V.-V. Telkki, M. Huttula, W. Cao, J.L. Provis, and M. Illikainen, "Field Strength of Network-Modifying Cation Dictates the Structure of (Na-Mg) Aluminosilicate Glasses," Frontiers in Materials, vol. 7, pp. (2020).
[66] Ilieva, A., B. Mihailova, Z. Tsintsov, and O. Petrov, "Structural state of microcrystalline opals: A Raman spectroscopic study," American Mineralogist, vol. 92, pp. 1325-1333, (2007).
[67] Hirose, T., K. Kihara, M. Okuno, S. Fujinami, and K. Shinoda, "X-ray, DTA and Raman studies of monoclinic tridymite and its higher temperature orthorhombic modification with varying temperature," Journal of Mineralogical and Petrological Sciences, vol. 100, pp. 55-69, (2005).
[68] Chen, K., L. Fang, and T. Zhang, "New zinc and bismuth doped glass sealants with substantially suppressed boron deposition and poisoning for solid oxide fuel cells," Journal of Materials Chemistry A, vol. 2, pp. 18655-18665, (2014).
[69] Kullberg, A.T.G., A.A.S. Lopes, J.P.B. Veiga, M.M.R.A. Lima, and R.C.C. Monteiro, "Formation and crystallization of zinc borosilicate glasses: Influence of the ZnO/B2O3 ratio," Journal of Non-Crystalline Solids, vol. 441, pp. 79-85, (2016).
[70] Ojovan, M.I., "Glass formation in amorphous SiO2 as a percolation phase transition in a system of network defects," Journal of Experimental and Theoretical Physics Letters, vol. 79, pp. 632-634, (2004).
[71] Richet, P., "GeO2 vs SiO2: Glass transitions and thermodynamic properties of polymorphs," Physics and Chemistry of Minerals, vol. 17, pp. 79-88, (1990).
[72] Hsiang, H.-I., C.-S. Hsi, C.-C. Huang, and S.-L. Fu, "Low temperature sintering and dielectric properties of BaTiO3 with glass addition," Materials Chemistry and Physics, vol. 113, pp. 658-663, (2009).
[73] Shim, S.-B., D.-S. Kim, S. Hwang, and H. Kim, "Wetting and surface tension of bismate glass melt," Thermochimica acta, vol. 496, pp. 93-96, (2009).
[74] Sato, S., Y. Nakano, A. Sato, and T. Nomura, "Mechanism of improvement of resistance degradation in Y-doped BaTiO3 based MLCCs with Ni electrodes under highly accelerated life testing," Journal of the European Ceramic Society, vol. 19, pp. 1061-1065, (1999).
[75] Ye, L., M.P. de Jong, T. Kudernac, W.G. van der Wiel, and J. Huskens, "Doping of semiconductors by molecular monolayers: monolayer formation, dopant diffusion and applications," Materials science in semiconductor processing, vol. 62, pp. 128-134, (2017).
[76] Jeon, S.-C., B.-K. Yoon, K.-H. Kim, and S.-J.L. Kang, "Effects of core/shell volumetric ratio on the dielectric-temperature behavior of BaTiO3," Journal of Advanced Ceramics, vol. 3, pp. 76-82, (2014).
[77] Henderson, D.W., "Thermal analysis of non-isothermal crystallization kinetics in glass forming liquids," Journal of Non-Crystalline Solids, vol. 30, pp. 301-315, (1979).
[78] Shintani, H. and H. Tanaka, "Frustration on the way to crystallization in glass," Nature Physics, vol. 2, pp. 200-206, (2006).