Abstract High-performance dielectric materials arouse persistently considerable attention due to their potential in the field of solid state capacitors. Ho-doped SrTiO3 ceramics with the composition of Ho0.02Sr0.97TiO3 were prepared by the solid state reaction technique. Structure, colossal dielectric behavior and relaxation mechanism of Ho0.02Sr0.97TiO3 ceramics were investigated in detail. The results indicated that Ho substitution of 0.02 content into the host materials maintain a single cubic perovskite structure. The Ho0.02Sr0.97TiO3 ceramics sintered at high temperature (1350 °C) show colossal permittivity (up to 4908 at 10 kHz) with low dielectric loss (about 0.03) at room temperature, and good dielectric stability over a broad frequency range of 100 Hz - 100 kHz as well. Four kinds of dielectric relaxations are present in a broad temperature range from −140 to +350 °C. Thermally stimulated depolarization current (TSDC) measurements were performed to explore the defects associated relaxation process. Four polarization relaxation peaks were detected in Ho0.02Sr0.97TiO3 ceramics, and three of them were assigned to defect dipole relaxations. There seems a possibility to form some defect dipoles because of the interactions among the defects available such as Sr vacancies, Ti3+, (HoSr)•, ionized oxygen vacancies and localized electrons. These defect clusters would give rise to relaxation behaviors and thus contribute to the colossal dielectric characteristics.

中文翻译：

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Ho 0.02 Sr 0.97 TiO 3 陶瓷的巨大介电常数和缺陷偶极子贡献

摘要 高性能介电材料因其在固态电容器领域的潜力而一直备受关注。采用固相反应技术制备了组成为Ho0.02Sr0.97TiO3的Ho掺杂SrTiO3陶瓷。详细研究了Ho0.02Sr0.97TiO3陶瓷的结构、巨介电行为和弛豫机制。结果表明，0.02 含量的 Ho 取代到主体材料中保持单立方钙钛矿结构。在高温 (1350 °C) 下烧结的 Ho0.02Sr0.97TiO3 陶瓷显示出巨大的介电常数（在 10 kHz 时高达 4908），室温下介电损耗低（约 0.03），并且在 100 的宽频率范围内具有良好的介电稳定性Hz - 100 kHz 也是如此。在 -140 至 +350 °C 的宽温度范围内存在四种介电弛豫。进行热刺激去极化电流 (TSDC) 测量以探索与弛豫过程相关的缺陷。在 Ho0.02Sr0.97TiO3 陶瓷中检测到四个极化弛豫峰，其中三个属于缺陷偶极弛豫。由于 Sr 空位、Ti3+、(HoSr)•、电离氧空位和定域电子等可用缺陷之间的相互作用，似乎有可能形成一些缺陷偶极子。这些缺陷簇会引起弛豫行为，从而有助于巨大的介电特性。在 Ho0.02Sr0.97TiO3 陶瓷中检测到四个极化弛豫峰，其中三个属于缺陷偶极弛豫。由于 Sr 空位、Ti3+、(HoSr)•、电离氧空位和定域电子等可用缺陷之间的相互作用，似乎有可能形成一些缺陷偶极子。这些缺陷簇会引起弛豫行为，从而有助于巨大的介电特性。在 Ho0.02Sr0.97TiO3 陶瓷中检测到四个极化弛豫峰，其中三个属于缺陷偶极弛豫。由于 Sr 空位、Ti3+、(HoSr)•、电离氧空位和定域电子等可用缺陷之间的相互作用，似乎有可能形成一些缺陷偶极子。这些缺陷簇会引起弛豫行为，从而有助于巨大的介电特性。