Scholarlink

<p>The rapid development of pulsed power technologies has imposed stringent requirements on high-performance dielectric materials. In this study, medium-entropy perovskite ceramics MeTiO<sub>3</sub> (Me = Ca, Sr, Ba, Mg) were designed and synthesized via a conventional solid-state reaction approach. The effects of the A-site cation on the microstructure and dielectric performance were investigated. The results showed that low A-site size mismatch (e.g., (Ca<sub>1/3</sub>Sr<sub>1/3</sub>Ba<sub>1/3</sub>)TiO<sub>3</sub>) yielded single-phase cubic perovskites, whereas higher mismatch promoted multiphase structures. Raman spectroscopy confirmed the presence of significant lattice distortion, and the incorporation of Mg<sup>2+</sup> enhanced the densification process and inhibited abnormal grain growth. Notably, in the (Ca<sub>1/3</sub>Ba<sub>1/3</sub>Mg<sub>1/3</sub>)TiO<sub>3</sub>(CBM) composition, the coexistence of (CaMg)TiO<sub>3</sub> and (BaMg)TiO<sub>3</sub> phases enhances interfacial effects. The partial incorporation of Mg<sup>2+</sup> into A-site and the formation of Mg-containing secondary phases induce ionic radius mismatch, lattice distortion, and the formation of defect dipoles, leading to a synergistic “lattice distortion–interfacial polarization” effect. Consequently, the CBM ceramics exhibit an ultralow dielectric loss (&lt; 10<sup>–3</sup>), a high breakdown strength of 240&#xa0;kV·cm<sup>−1</sup>, and excellent temperature stability, with the temperature coefficient of capacitance (<i>TCC</i><sub><i>25℃</i></sub>) varying by less than 5% over the range of − 70–150&#xa0;℃. These results highlight the medium-entropy perovskite ceramics as promising candidates for pulsed power devices and next-generation advanced dielectric capacitors.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Microstructure and dielectric properties of medium-entropy MeTiO3 (Me = Ca, Sr, Ba, Mg) ceramics with A-site cation disorder

  • 期刊论文

  • 发表日期：

    2026年4月3日

查看全文
  • Bingyan Gao,
  • Xiaoyu Xu,
  • Kaixuan Chang,
  • Guoxin Hu,
  • Yan Fang,
  • Yilin Chen,
  • Ziyang Cheng,
  • Jiayu Cai,
  • Xinhao Ma,
  • Jie Xu,
  • Feng Gao

摘要

The rapid development of pulsed power technologies has imposed stringent requirements on high-performance dielectric materials. In this study, medium-entropy perovskite ceramics MeTiO3 (Me = Ca, Sr, Ba, Mg) were designed and synthesized via a conventional solid-state reaction approach. The effects of the A-site cation on the microstructure and dielectric performance were investigated. The results showed that low A-site size mismatch (e.g., (Ca1/3Sr1/3Ba1/3)TiO3) yielded single-phase cubic perovskites, whereas higher mismatch promoted multiphase structures. Raman spectroscopy confirmed the presence of significant lattice distortion, and the incorporation of Mg2+ enhanced the densification process and inhibited abnormal grain growth. Notably, in the (Ca1/3Ba1/3Mg1/3)TiO3(CBM) composition, the coexistence of (CaMg)TiO3 and (BaMg)TiO3 phases enhances interfacial effects. The partial incorporation of Mg2+ into A-site and the formation of Mg-containing secondary phases induce ionic radius mismatch, lattice distortion, and the formation of defect dipoles, leading to a synergistic “lattice distortion–interfacial polarization” effect. Consequently, the CBM ceramics exhibit an ultralow dielectric loss (< 10–3), a high breakdown strength of 240 kV·cm−1, and excellent temperature stability, with the temperature coefficient of capacitance (TCC25℃) varying by less than 5% over the range of − 70–150 ℃. These results highlight the medium-entropy perovskite ceramics as promising candidates for pulsed power devices and next-generation advanced dielectric capacitors.