电介质陶瓷作为电子元器件的核心材料，在电子信息、航天航空以及国防军事等领域有着广泛的应用。但是随着现代电力电子技术的快速发展，单一功能的电介质陶瓷材料难以满足人们对多功能性的需求，因此多功能陶瓷材料的研究和开发开始得到越来越多的关注。钛酸锶（SrTiO₃）陶瓷材料由于具有优异的电容-压敏双功能特性，在防浪涌和储能领域展现出广阔的应用前景，因此逐渐成为多功能陶瓷材料研究的热点。本课题通过施-受主复合掺杂的方式对SrTiO₃陶瓷的介电特性、非线性特性及储能特性进行调控，并详细讨论了物相结构、微观形貌以及缺陷结构对电学性能的影响，获得了综合电学性能优异的SrTiO₃多功能陶瓷材料。

首先，采用固相烧结法制备了SrTiO₃陶瓷，研究了不同烧结温度对SrTiO₃陶瓷微观结构和电学性能的影响，结果表明SrTiO₃陶瓷的最佳烧结温度为1200℃。其次，采用Ta、Mg掺杂制备了SrTa_0.01Ti_0.99O₃、SrMg_0.01Ti_0.99O₃和不同组分Sr(Ta_2/3Mg_1/3)_xTi_1-xO₃（0≤x≤0.06）陶瓷，系统研究了不同掺杂方式及掺杂浓度对SrTiO₃陶瓷在不同电极下的介电特性、非线性特性以及储能特性的影响。结果表明，在低频范围内的介电常数随频率的增大而降低，在高频范围内的介电常数具有良好的频率稳定性。通过涂覆不同电极发现，银电极陶瓷在低频下的高介电常数和介电损耗峰是由SBLC效应引起的，金电极陶瓷在高频范围内呈现出介电常数降低、介电损耗升高的现象可由IBLC效应解释。通过Arrhenius拟合发现，高温处的介电弛豫主要是与氧空位有关的缺陷偶极子导致的。与SrTiO₃陶瓷相比，组分x=0.05的综合电学性能最佳，同时改善了介电特性及储能特性，在25℃、1MHz下拥有高介电常数（184）和低介电损耗（0.005），在75kV/cm下拥有较高的功率密度（2.77 MW/cm³）和储能密度（0.038 J/cm³），但非线性特性未得到提升。

最后，采用Ta、Tb元素对SrTiO₃陶瓷的Ti位进行掺杂，制备出了SrTa_0.01Ti_0.99O₃、SrTb_0.01Ti_0.99O₃和不同组分Sr(Ta_0.5Tb_0.5)_yTi_1-yO₃（0≤y≤0.06）陶瓷，系统研究了掺杂浓度对SrTiO₃陶瓷微观结构及电学性能的影响，探讨了不同电学性能之间的关联性。结果表明，所有组分在低频下的高介电常数也是源于SBLC效应，高介电损耗是由SBLC和电导共同引起的。此外，高温处的介电弛豫主要是与氧空位和偏离中心Ti³⁺有关的缺陷偶极子导致的。与SrTiO₃陶瓷相比，组分y=0.03的综合电学性能最佳，同时提升了介电特性、非线性特性及储能特性。在25℃、1MHz下组分y=0.03拥有高介电常数（193）、低介电损耗（0.005）以及良好的频率稳定性；在非线性特性方面，组分y=0.03提高了非线性系数（2.84），击穿场强为14.14 kV/cm；在储能特性方面，组分y=0.03在100 kV/cm下拥有最高的功率密度（6.01 MW/cm³）和储能密度（0.047J /cm³）。

As the core material of electronic components, dielectric ceramics have wide applications in fields such as electronic information, aerospace, and national defense and military. However, with the rapid development of modern power electronics technology, single functional dielectric ceramic materials are unable to meet people's demand for multifunctionality. Therefore, the research and development of multifunctional ceramic materials are receiving increasing attention. Strontium titanate (SrTiO₃) ceramic materials have shown broad application prospects in the fields of surge protection and energy storage due to their excellent capacitance-varistor dual-functional characteristics, so have gradually become a hot topic in the research of multifunctional ceramic materials. This study regulates the dielectric, nonlinear and energy storage properties of SrTiO₃ ceramics through donor-acceptor composite doping, and discusses in detail the effects of phase structure, microstructure, and defect structure on electrical properties, and multifunctional SrTiO₃ ceramic materials with excellent comprehensive electrical properties are obtained.

Firstly, SrTiO₃ ceramics were prepared using solid-state sintering method, and the effects of different sintering temperatures on the microstructure and electrical properties of SrTiO₃ ceramics were investigated. The results showed that the optimal sintering temperature for SrTiO₃ ceramics was 1200℃. Secondly, SrTa_0.01Ti_0.99O₃, SrMg_0.01Ti_0.99O₃, and Sr(Ta_2/3Mg_1/3)_xTi_1-xO₃ (0 ≤ x ≤ 0.06) ceramics were synthesized with Ta and Mg doping. Various doping methods and concentrations were systematically studied to evaluate their effects on the dielectric, nonlinear, and energy storage properties of SrTiO₃ ceramics with different electrodes. The findings indicated that the dielectric constant at low frequencies decreased with increasing frequency, while it exhibited good frequency stability at high frequencies. Coating with different electrodes revealed that the high dielectric constant and dielectric loss peak at low frequencies in silver electrode ceramics were due to the SBLC effect, whereas the decrease in dielectric constant and increase in dielectric loss at high frequencies in gold electrode ceramics were attributed to the IBLC effect. Arrhenius fitting suggested that the high-temperature dielectric relaxation was primarily caused by defect dipoles related to oxygen vacancies. Compared to SrTiO₃ ceramics, the composition with x = 0.05 exhibited the best comprehensive electrical properties, simultaneously improving dielectric and energy storage characteristics. At 25°C and 1 MHz, it showed a high dielectric constant (184) and low dielectric loss (0.005), while at 75 kV/cm, it demonstrated higher power density (2.77 MW/cm³) and energy density (0.038 J/cm³). However, its nonlinear characteristics did not show improvement.

Finally, doping of SrTiO₃ ceramics with Ta and Tb elements at the Ti site resulted in the synthesis of SrTa_0.01Ti_0.99O₃, SrTb_0.01Ti_0.99O₃, and various compositions of Sr(Ta_0.5Tb_0.5)_yTi_1-yO₃ (0 ≤ y ≤ 0.06). The effects of doping concentration on the microstructure and electrical properties of SrTiO₃ ceramics were systematically studied, along with the correlations among different electrical properties. The results showed that the high dielectric constant at low frequencies for all compositions was also due to the SBLC effect, while the high dielectric loss was caused by both SBLC and conductivity effects. Additionally, the high-temperature dielectric relaxation was primarily related to defect dipoles associated with oxygen vacancies and off-center Ti³⁺ ions. Compared to SrTiO₃ ceramics, the composition with y = 0.03 exhibited the best comprehensive electrical properties, enhancing dielectric, nonlinear, and energy storage characteristics. At 25°C and 1 MHz, the y = 0.03 composition showed a high dielectric constant (193), low dielectric loss (0.005), and good frequency stability. In terms of nonlinear characteristics, it increased the nonlinear coefficient (2.84) with a breakdown field strength of 14.14 kV/cm. Regarding energy storage properties, the y = 0.03 composition demonstrated the highest power density (6.01 MW/cm³) and energy density (0.047 J/cm³) at 100 kV/cm.

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