鈦酸鋇具有高的介電常數及低介電損耗等特性，被廣泛應用在多層陶瓷電容(MLCC)作為介電陶瓷材料，但純鈦酸鋇達到緻密化所需的燒結溫度一般超過1300℃，但是在高溫下會使內電極發生劇烈收縮產生裂縫導致元件發生短路，影響電容器的可靠性。在鈦酸鋇陶瓷粉末中添加燒結助劑是有效降低燒結溫度的方法，而硼矽酸鹽類的玻璃具有低軟化溫度及熔融溫度，是良好的助燒結劑候選材料。
本研究利用濕式化學法合成CaO-B2O3-SiO2 (CBS) 奈米玻璃，透過調整製程參數及CBS 玻璃中的CaO /B2O3/ SiO2 的比例，探討溶劑、螯合劑與CBS 成分組成，對助燒結效果及鈦酸鋇介電性質的影響。使用EDS 與XRD 確認CBS 玻璃成分的均勻性以及結晶行為，並以FTIR 及Raman 光譜分析玻璃分子結構，使用DTA 分析玻璃之熱性質。為確認CBS 玻璃對於鈦酸鋇陶瓷體的助燒結性質，本研究將CBS 玻璃加入鈦酸鋇中製成陶瓷體，以DIL 確認熱收縮溫度區間，以1150-1250ºC 分別進行鈦酸鋇陶瓷體的燒結，並分析其相對密度變化趨勢以及介電性質表現。本研究透過調整CBS玻璃中的CaO /B2O3/ SiO2 的比例，從助燒結效果以及介電性質，評估對鈦酸鋇介電陶瓷最佳玻璃組成。
研究結果顯示，鈦酸鋇陶瓷體之介電性質與CBS 之成分組成密切相關，其中CaO不僅扮演玻璃結構調整劑角色，決定玻璃結構的均勻性，進而改變CBS 玻璃的熔點以及其對鈦酸鋇陶瓷體的助燒結效果。除此之外，根據結構精算結果確認，Ca 離子在燒結過程中會取代鈦酸鋇的Ti 位點，提高鈦酸鋇的還原焓值，降低在還原氣氛下燒結產生的氧空缺，同時有效提升摻雜氧化物的擴散速率，使其於鈦酸鋇晶粒中形成較厚的擴散殼層，對於電阻率有顯著提升的效果。
綜合考慮助燒結特性及對鈦酸鋇介電性質的影響，14.3CaO-14.3B2O3-71.4SiO2 （WC2B2S10）的組成可以使鈦酸鋇在1150℃下燒結緻密，並大幅提高鈦酸鋇陶瓷體的絕緣電阻率同時保有相對較高的介電常數與低介電損耗，對於降低鈦酸鋇在居禮溫度下的電容值變化率亦有所助益。

Barium titanate (BaTiO3) is widely used as a dielectric ceramic material in multilayer ceramic capacitors (MLCC) due to its high dielectric constant and low dielectric loss. However, the densification temperature of pure BaTiO3 typically exceeds 1300°C, which can cause significant shrinkage and cracking of the internal electrodes at high temperatures, leading to short circuits and reduced reliability of the capacitors. Adding sintering aids to BaTiO3 ceramic powders is an effective way to lower the sintering temperature. Borosilicate glass, with its low softening and melting temperatures, is a promising candidate for a sintering aid.
In this study, CaO-B2O3-SiO2 (CBS) nano glass was synthesized using a wet chemical method. By adjusting the CaO/B2O3/SiO2 ratio in the CBS glass, the effects of CBS composition on the sintering aid performance and the dielectric properties of BaTiO3 were investigated. The results showed that CaO not only acted as a glass network modifier, affecting the homogeneity of the glass structure and changing the melting point of CBS glass, but also influenced the sintering aid effect on BaTiO3 ceramics. Additionally, structural refinement results confirmed that Ca ions would replace Ti sites in BaTiO3 during the sintering process, increasing the reduction enthalpy of BaTiO3 and reducing the oxygen vacancy formation under a reducing atmosphere. CBS glass also effectively enhanced the diffusion rate of doped oxides, forming a thicker diffusion shell in BaTiO3 grains and significantly improving the resistivity. Considering both the sintering aid characteristics and the impact on the dielectric properties of BaTiO3, a composition of 14.3CaO-14.3B2O3-71.4SiO2 (WC2B2S10) was found to allow for dense sintering of BaTiO3 at 1150°C, significantly increasing the insulation resistivity of BaTiO3 ceramics while maintaining a relatively high dielectric constant and low dielectric loss. This composition also helped reduce the variation in capacitance at the Curie temperature.

[1] Hu, D., Pan, Z., Tan, X., Yang, F., Ding, J., Zhang, X., Li, P., Liu, J., Zhai, J., and Pan, H., "Optimization the energy density and efficiency of BaTiO3-based ceramics for capacitor applications," Chemical Engineering Journal, vol. 409, p. 127375, 2021.
[2] Li, W.-B., Zhou, D., Xu, R., Wang, D.-W., Su, J.-Z., Pang, L.-X., Liu, W.-F., and Chen, G.-H., "BaTiO3-based multilayers with outstanding energy storage performance for high temperature capacitor applications," ACS Applied Energy Materials, vol. 2, no. 8, pp. 5499-5506, 2019.
[3] Fu, D., Itoh, M., and Koshihara, S.-y., "Crystal growth and piezoelectricity of BaTiO3-CaTiO3 solid solution," Applied Physics Letters, vol. 93, no. 1, 2008.
[4] Lee, M., Renshof, J. R., van Zeggeren, K. J., Houmes, M. J., Lesne, E., Šiškins, M., van Thiel, T. C., Guis, R. H., van Blankenstein, M. R., and Verbiest, G. J., "Ultrathin piezoelectric resonators based on graphene and free‐standing single‐crystal BaTiO3," Advanced Materials, vol. 34, no. 44, p. 2204630, 2022.
[5] Cha, S. H. and Han, Y. H., "Effects of oxygen vacancies on relaxation behavior of Mg-doped BaTiO3," Japanese journal of applied physics, vol. 45, no. 10R, p. 7797, 2006.
[6] Cha, S. H. and Han, Y. H., "Effects of Mn doping on dielectric properties of Mg-doped BaTiO3," Journal of applied physics, vol. 100, no. 10, 2006.
[7] Lu, D.-Y. and Cui, S.-Z., "Defects characterization of Dy-doped BaTiO3 ceramics via electron paramagnetic resonance," Journal of the European Ceramic Society, vol. 34, no. 10, pp. 2217-2227, 2014.
[8] Tsur, Y., Dunbar, T. D., and Randall, C. A., "Crystal and defect chemistry of rare earth cations in BaTiO3," Journal of electroceramics, vol. 7, pp. 25-34, 2001.
[9] Dai, B., Hu, X., Yin, R., Bai, W., Wen, F., Deng, J., Zheng, L., Du, J., Zheng, P., and Qin, H., "Piezoelectric grain-size effects of BaTiO3 ceramics under different sintering atmospheres," Journal of Materials Science: Materials in Electronics, vol. 28, no. 11, pp. 7928-7934, 2017.
[10] Young, A., Hilmas, G., Zhang, S. C., and Schwartz, R. W., "Effect of liquid‐phase sintering on the breakdown strength of barium titanate," Journal of the American Ceramic Society, vol. 90, no. 5, pp. 1504-1510, 2007.
[11] Jeon, H.-P., Lee, S.-K., Kim, S.-W., and Choi, D.-K., "Effects of BaO-B2O3-SiO2 glass additive on densification and dielectric properties of BaTiO3 ceramics," Materials Chemistry and Physics, vol. 94, no. 2-3, pp. 185-189, 2005.
[12] Hsiang, H.-I., Hsi, C.-S., Huang, C.-C., and Fu, S.-L., "Low temperature sintering and dielectric properties of BaTiO3 with glass addition," Materials Chemistry and Physics, vol. 113, no. 2-3, pp. 658-663, 2009.
[13] Shih, Y.-T. and Jean, J.-H., "Low-fire processing of microwave (Ca1-xSrx)(Zr1-yMny)O3 dielectric with Li2O-B2O2-SiO2 glass in H2/N2.," Ceramics International vol. 43, pp. 306-331, 2017.
[14] Sun, C., Wang, X., and Li, L., "Low sintering of X7R ceramics based on barium titanate with SiO2-B2O3-Li2O sintering additives in reducing atmosphere," Ceramics International, vol. 38, pp. S49-S52, 2012.
[15] 王延齡, "以濕式化學法製備Li2O-B2O3-SiO2玻璃及其於鈦酸鋇MLCC之助燒結性質研究," 國立成功大學資源工程所碩士論文, 2023.
[16] Zhao, Q., Gong, H., Wang, X., Luo, B., and Li, L., "Influence of BaO-CaO-SiO2 on dielectric properties and reliability of BaTiO3‐based ceramics," physica status solidi (a), vol. 213, no. 4, pp. 1077-1081, 2016.
[17] Wang, S.-F., Lai, B.-C., Hsu, Y.-F., and Lu, C.-A., "Dielectric properties of CaO-B2O3-SiO2 glass-ceramic systems in the millimeter-wave frequency range of 20-60 GHz," Ceramics International, vol. 47, no. 16, pp. 22627-22635, 2021.
[18] Kingma, K. J. and Hemley, R. J., "Raman spectroscopic study of microcrystalline silica," American Mineralogist, vol. 79, no. 3-4, pp. 269-273, 1994.
[19] Buzatu, A. and Buzgar, N., "The Raman study of single-chain silicates," Analele Stiintifice de Universitatii AI Cuza din Iasi. Sect. 2, Geologie, vol. 56, no. 1, p. 107, 2010.
[20] Zhu, H., Fu, R., Agathopoulos, S., Fang, J., Li, G., and He, Q., "Crystallization behaviour and properties of BaO-CaO-B2O3-SiO2 glasses and glass-ceramics for LTCC applications," Ceramics International, vol. 44, no. 9, pp. 10147-10153, 2018.
[21] Voron'ko, Y. K., Sobol', A., Ushakov, S., Guochang, J., and Jinglin, Y., "Phase transformations and melt structure of calcium metasilicate," Inorganic materials, vol. 38, pp. 825-830, 2002.
[22] Yan, T., Zhang, W., Chen, X., Wang, F., and Bai, S., "Sintering densification behaviors and crystallization characteristics of glass-ceramics formed by two types of CaO-B2O3-SiO2 glass," Journal of Materials Science: Materials in Electronics, vol. 30, pp. 10352-10359, 2019.
[23] Wang, S.-F., Lai, B.-C., Hsu, Y.-F., and Lu, C.-A., "Physical and structural characteristics of sol-gel derived CaO-B2O3-SiO2 glass-ceramics and their dielectric properties in the 5G millimeter-wave bands," Ceramics International, vol. 48, no. 7, pp. 9030-9037, 2022.
[24] He, F., He, Z., Xie, J., and Li, Y., "IR and Raman spectra properties of Bi2O3-ZnO-B2O3-BaO quaternary glass system," American Journal of Analytical Chemistry, vol. 5, no. 16, p. 1142, 2014.
[25] Li, B., Wang, Z., and Xia, Q., "Influence of Nd2O3 Addition on Sintering Kinetics, Microstructures, and Properties of CaO-B2O3-SiO2 Glass-Ceramics for Packages," Journal of Electronic Materials, vol. 48, pp. 7923-7928, 2019.
[26] Stebbins, J. F. and Xu, Z., "NMR evidence for excess non-bridging oxygen in an aluminosilicate glass," Nature, vol. 390, no. 6655, pp. 60-62, 1997.
[27] Yang, Y., Hao, H., Zhang, L., Chen, C., Luo, Z., Liu, Z., Yao, Z., Cao, M., and Liu, H., "Structure, electrical and dielectric properties of Ca substituted BaTiO3 ceramics," Ceramics International, vol. 44, no. 10, pp. 11109-11115, 2018.
[28] Jeon, S.-C., Yoon, B.-K., Kim, K.-H., and Kang, S.-J. L., "Effects of core/shell volumetric ratio on the dielectric-temperature behavior of BaTiO3," Journal of Advanced Ceramics, vol. 3, pp. 76-82, 2014.
[29] Sun, J., Bingcheng Luo, and Li., H., "A review on the conventional capacitors, supercapacitors, and emerging hybrid Ion capacitors: Past, present, and future.," Advanced Energy and Sustainability Research, vol. 3, no. 6, 2022, Art no. 2100191.
[30] Panda, M., Joshi, S., Annalakshmi, O., Srinivas, C., and Venkatraman, B., "Surface mount multilayer ceramic capacitors as optically stimulated luminescent dosimeters," Radiation Physics and Chemistry, vol. 213, p. 111253, 2023.
[31] Wang, J., Meng, F., Ma, X., Xu, M., and Chen, L., "Lattice, elastic, polarization, and electrostrictive properties of BaTiO3 from first-principles," Journal of Applied Physics, vol. 108, no. 3, 2010.
[32] Das, A., "Characterizations of Lead Free BNT-BT-KNN Ceramics Synthesized by Microwave Technique," 2014.
[33] Paunovic, V., Mitic, V., Djordjevic, M., and Prijic, Z., "Niobium doping effect on BaTiO3 structure and dielectric properties," Ceramics International, vol. 46, no. 6, pp. 8154-8164, 2020.
[34] Peng, W., Li, L., Yu, S., Yang, P., and Xu, K., "Dielectric properties, microstructure and charge compensation of MnO2-doped BaTiO3-based ceramics in a reducing atmosphere," Ceramics International, vol. 47, no. 20, pp. 29191-29196, 2021.
[35] Paunovic, V., Mitic, V., and Kocic, L., "Dielectric characteristics of donor-acceptor modified BaTiO3 ceramics," Ceramics International, vol. 42, no. 10, pp. 11692-11699, 2016.
[36] German, R. M., Suri, P., and Park, S. J., "Liquid phase sintering," Journal of materials science, vol. 44, pp. 1-39, 2009.
[37] Marion, J., Hsueh, C., and Evans, A., "Liquid‐phase sintering of ceramics," Journal of the American Ceramic Society, vol. 70, no. 10, pp. 708-713, 1987.
[38] Assink, R. A. and Kay, B. D., "Sol-gel kinetics I. Functional group kinetics," Journal of Non-Crystalline Solids, vol. 99, no. 2-3, pp. 359-370, 1988.
[39] Gnado, J., Dhamelincourt, P., Pelegris, C., Traisnel, M., and Mayot, A. L. M., "Raman spectra of oligomeric species obtained by tetraethoxysilane hydrolysis-polycondensation process," Journal of non-crystalline solids, vol. 208, no. 3, pp. 247-258, 1996.
[40] Marino, I.-G., Lottici, P. P., Bersani, D., Raschellà, R., Lorenzi, A., and Montenero, A., "Micro-Raman monitoring of solvent-free TEOS hydrolysis," Journal of non-crystalline solids, vol. 351, no. 6-7, pp. 495-498, 2005.
[41] Brinker, C. J. and Scherer, G. W., "Sol→gel→glass: I. Gelation and gel structure," Journal of Non-Crystalline Solids, vol. 70, no. 3, pp. 301-322, 1985.
[42] Brinker, C., Keefer, K., Schaefer, D., and Ashley, C., "Sol-gel transition in simple silicates," Journal of Non-Crystalline Solids, vol. 48, no. 1, pp. 47-64, 1982.
[43] Aelion, R., Loebel, A., and Eirich, F., "Hydrolysis of ethyl silicate," Journal of the American chemical society, vol. 72, no. 12, pp. 5705-5712, 1950.
[44] Stöber, W., Fink, A., and Bohn, E., "Controlled growth of monodisperse silica spheres in the micron size range," Journal of colloid and interface science, vol. 26, no. 1, pp. 62-69, 1968.
[45] Kim, K. D. and Kim, H. T., "Formation of silica nanoparticles by hydrolysis of TEOS using a mixed semi-batch/batch method," Journal of sol-gel science and technology, vol. 25, pp. 183-189, 2002.
[46] Ren, G., Su, H., and Wang, S., "The combined method to synthesis silica nanoparticle by Stöber process," Journal of Sol-Gel Science and Technology, vol. 96, pp. 108-120, 2020.
[47] Qi, D., Lin, C., Zhao, H., Liu, H., and Lü, T., "Size regulation and prediction of the SiO2 nanoparticles prepared via Stöber process," Journal of Dispersion Science and Technology, vol. 38, no. 1, pp. 70-74, 2017.
[48] Pechini, M. P., "Method of preparing lead and alkaline earth titanates and niobates and coating method using the same to form a capacitor," ed: Google Patents, 1967.
[49] Danks, A. E., Hall, S. R., and Schnepp, Z., "The evolution of ‘sol-gel’chemistry as a technique for materials synthesis," Materials Horizons, vol. 3, no. 2, pp. 91-112, 2016.
[50] Zachariasen, W. H., "The atomic arrangement in glass," Journal of the American Chemical Society, vol. 54, no. 10, pp. 3841-3851, 1932.
[51] Gao, Y., Seles, M. A., and Rajan, M., "Role of bioglass derivatives in tissue regeneration and repair: A review," Reviews on Advanced Materials Science, vol. 62, no. 1, p. 20220318, 2023.
[52] Barlet, M., Kerrache, A., Delaye, J.-M., and Rountree, C. L., "SiO2-Na2O-B2O3 density: a comparison of experiments, simulations, and theory," Journal of non-crystalline solids, vol. 382, pp. 32-44, 2013.
[53] Liu, F., Guo, X., and Yang, G., "Crystallization of gels in the SiO2-ZrO2-B2O3 system," Journal of materials science, vol. 36, pp. 579-585, 2001.
[54] Zhou, F., Xu, D., Shi, M., and Bi, Y., "Investigation on microstructure and its transformation mechanisms of B2O3-SiO2-Al2O3-CaO brazing flux system," High Temperature Materials and Processes, vol. 39, no. 1, pp. 88-95, 2020.
[55] Muralidharan, P., Venkateswarlu, M., and Satyanarayana, N., "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, no. 6-7, pp. 583-594, 2005.
[56] 郑伟宏, 盛丽, 周颖, 刘欣悦, 崔晶晶, and 彭志钢, "ZnO 对 ZnO-B2O3-SiO2 低熔点玻璃结构与性能的影响," 硅酸盐通报, vol. 36, no. 4, pp. 1143-1148, 2017.
[57] Chen, M., Liao, J.-L., and Hsiang, H.-I., "Effects of Li-B-Si-Ca-Mn glass addition on the densification, microstructure, and dielectric properties of (Ca, Sr)(Zr, Ti)O3 ceramics," Ceramics International, vol. 48, no. 19, pp. 28023-28029, 2022.
[58] Wu, Z., Liu, H., Cao, M., Shen, Z., Yao, Z., Hao, H., and Luo, D., "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, no. 1350, pp. 345-349, 2008.
[59] Shen, Z., Liu, H., Wu, Z., Yao, Z., Cao, M., and Luo, D., "Preparation and dielectric properties of Sr (Ti0.95Zr0.05)O3 ceramics doped with CaO-TiO2-SiO2 (CTS)," Materials Science and Engineering: B, vol. 136, no. 1, pp. 11-14, 2007.
[60] Li, Y., Liu, H., Yao, Z., Xu, J., Cui, Y., Cao, M., Hao, H., and Yu, Z., "The Effect of ZnO-B2O3-SiO2 Additive on Sintering and Dielectric Properties of Ba0.3Sr0.7TiO3 Ceramics," Ferroelectrics, vol. 403, no. 1, pp. 45-53, 2010.
[61] Yao, C., Dong, X., Gao, G., Sha, F., and Xu, D., "Microstructure and adsorption properties of MTMS/TEOS Co-precursor silica aerogels dried at ambient pressure," Journal of Non-Crystalline Solids, vol. 562, p. 120778, 2021.
[62] Vaqueiro, P. and Lopez-Quintela, M., "Influence of complexing agents and pH on yttrium− iron garnet synthesized by the sol-gel method," Chemistry of materials, vol. 9, no. 12, pp. 2836-2841, 1997.
[63] Hu, Y., Fei, L., Zhang, Y., Yuan, J., Wang, Y., and Gu, H., "Synthesis of bismuth ferrite nanoparticles via a wet chemical route at low temperature," Journal of Nanomaterials, vol. 2011, pp. 1-6, 2011.
[64] Kaur, R., Singh, S., and Pandey, O., "Structural variation in gamma ray irradiated PbO-Na2O-B2O3-SiO2 glasses," Solid state communications, vol. 188, pp. 40-44, 2014.
[65] Fernandes, J. S., Gentile, P., Moorehead, R., Crawford, A., Miller, C. A., Pires, R. A., Hatton, P. V., and Reis, R. L., "Design and properties of novel substituted borosilicate bioactive glasses and their glass-ceramic derivatives," Crystal Growth & Design, vol. 16, no. 7, pp. 3731-3740, 2016.
[66] Han, J., Lai, Y., Xiang, Y., Wu, S., Zeng, Y., Yang, H., Mao, Y., and Yang, Y., "Structure and crystallization behavior of Al containing glasses in the CaO-B2O3-SiO2 system," RSC Advances, vol. 7, no. 24, pp. 14709-14715, 2017.
[67] Xiang, Y., Han, J., Lai, Y., Li, S., Wu, S., Xu, Y., Zeng, Y., Zhou, L., and Huang, Z., "Glass structure, phase transformation and microwave dielectric properties of CaO-B2O3-SiO2 glass-ceramics with addition of La2O3," Journal of Materials Science: Materials in Electronics, vol. 28, pp. 9911-9918, 2017.
[68] Shuai, C., Mao, Z., Han, Z., Peng, S., and Li, Z., "Fabrication and characterization of calcium silicate scaffolds for tissue engineering," Journal of Mechanics in Medicine and Biology, vol. 14, no. 04, p. 1450049, 2014.
[69] Baek, J.-S., Jo, N.-B., and Kim, E.-S., "Microwave Dielectric Properties of β-CaSiO3 Glass-Ceramics Prepared Using Two-Step Heat Treatment," Processes, vol. 9, no. 12, p. 2180, 2021.
[70] He, D., Zhong, H., and Gao, C., "Crystallization kinetics, structure and dielectric properties of CaO-B2O3-SiO2 glass-ceramics nucleated by composite nucleating agents," Journal of Materials Science: Materials in Electronics, vol. 30, pp. 18070-18079, 2019.
[71] Pan, H., Zhao, X., Zhang, X., Zhang, K., Li, L., Li, Z., Lam, W., Lu, W., Wang, D., and Huang, W., "Strontium borate glass: potential biomaterial for bone regeneration," Journal of the Royal Society Interface, vol. 7, no. 48, pp. 1025-1031, 2010.
[72] Rada, S., Culea, M., Neumann, M., and Culea, E., "Structural role of europium ions in lead-borate glasses inferred from spectroscopic and DFT studies," Chemical Physics Letters, vol. 460, no. 1-3, pp. 196-199, 2008.
[73] Wei, P.-f., Zhou, H.-q., Zhu, H.-k., Dai, B., and Wang, J., "Microstructure and microwave dielectric properties of CaO-B2O3-SiO2 glass ceramics with various B2O3 contents," Journal of Central South University, vol. 18, no. 5, pp. 1359-1364, 2011.
[74] Shao, G., Wu, X., Kong, Y., Cui, S., Shen, X., Jiao, C., and Jiao, J., "Thermal shock behavior and infrared radiation property of integrative insulations consisting of MoSi2/borosilicate glass coating and fibrous ZrO2 ceramic substrate," Surface and Coatings Technology, vol. 270, pp. 154-163, 2015.
[75] Rao, T., Kumar, A. R., Neeraja, K., Veeraiah, N., and Reddy, M. R., "Optical and structural investigation of Eu3+ ions in Nd3+ co-doped magnesium lead borosilicate glasses," Journal of Alloys and Compounds, vol. 557, pp. 209-217, 2013.
[76] Zhou, X., Li, E., Yang, S., Li, B., Tang, B., Yuan, Y., and Zhang, S., "Preparation and properties of low temperature sintered CaO-B2O3-SiO2 microwave dielectric ceramics using the solid-state reaction," Materials Science-Poland, vol. 31, pp. 404-409, 2013.
[77] Zhang, X., Liu, C., and Jiang, M., "Effect of B2O3 on the Melt Structure and Viscosity of CaO-SiO2 System," steel research international, vol. 93, no. 5, p. 2100520, 2022.
[78] Su, C., Pithan, C., Hennings, D., and Waser, R., "Proton defects in BaTiO3: New aspects regarding the re-oxidation of dielectric materials fired in reducing atmospheres," Journal of the European Ceramic Society, vol. 33, no. 15-16, pp. 3007-3013, 2013.
[79] Wang, M., Xue, K., Zhang, K., and Li, L., "Dielectric properties of BaTiO3-based ceramics are tuned by defect dipoles and oxygen vacancies under a reducing atmosphere," Ceramics International, vol. 48, no. 15, pp. 22212-22220, 2022.
[80] Harizanova, R., Bocker, C., Avdeev, G., Slavov, S., Costa, L. C., Avramova, I., and Rüssel, C., "Microstructure and electrical conduction of iron-doped barium titanate glass-ceramics," Journal of Non-Crystalline Solids, vol. 560, p. 120711, 2021.
[81] Hsiang, H.-I., Yang, Y.-H., Huang, C.-Y., and Yang, K.-H., "Dielectric properties of BaTiO3 and Ba0.95Ca0.05TiO3 sintered in a reducing atmosphere," Ceramics International, vol. 49, no. 17, pp. 28751-28757, 2023.
[82] Sharma, S., Pandey, H., Kumar, M., and Chhoker, S., "Room temperature ferromagnetism and electrical properties of Mn-doped Zn2SnO4 nanorods," Superlattices and Microstructures, vol. 120, pp. 161-169, 2018.
[83] Long, C., Liu, L., Song, H., Wu, H., Zheng, K., Ren, W., and Ding, X., "Achieving excellent energy storage performances and eminent charging-discharging capability in donor (1-x)BT-x(BZN-Nb) relaxor ferroelectric ceramics," Chemical Engineering Journal, vol. 459, p. 141490, 2023.
[84] Srisombat, L., Ananta, S., Singhana, B., Lee, T. R., and Yimnirun, R., "Chemical investigation of Fe3+/Nb5+-doped barium titanate ceramics," Ceramics International, vol. 39, pp. S591-S594, 2013.
[85] Post, P., Wurlitzer, L., Maus-Friedrichs, W., and Weber, A. P., "Characterization and applications of nanoparticles modified in-flight with silica or silica-organic coatings," Nanomaterials, vol. 8, no. 7, p. 530, 2018.
[86] Shannon, R. D., "Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides," Acta crystallographica section A: crystal physics, diffraction, theoretical and general crystallography, vol. 32, no. 5, pp. 751-767, 1976.
[87] Sakabe, Y., Wada, N., Hiramatsu, T., and Tonogaki, T., "Dielectric properties of fine-grained BaTiO3 ceramics doped with CaO," Japanese journal of applied physics, vol. 41, no. 11S, p. 6922, 2002.
[88] Khedhri, M. H., Abdelmoula, N., Khemakhem, H., Douali, R., and Dubois, F., "Structural, spectroscopic and dielectric properties of Ca-doped BaTiO3," Applied Physics A, vol. 125, pp. 1-13, 2019.
[89] Jiang, X., Hao, H., Yang, Y., Zhou, E., Zhang, S., Wei, P., Cao, M., Yao, Z., and Liu, H., "Structure and enhanced dielectric temperature stability of BaTiO3-based ceramics by Ca ion B site-doping," Journal of Materiomics, vol. 7, no. 2, pp. 295-301, 2021.