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<p>Microwave sintering was employed to rapidly fabricate high-performance zinc silicate ceramics, and the influence of sintering duration on the microstructure and dielectric properties of stoichiometric Zn<sub>2.0</sub>SiO<sub>4.0</sub> and non-stoichiometric Zn<sub>1.8</sub>SiO<sub>3.8</sub> was systematically investigated. The Zn<sub>2.0</sub>SiO<sub>4.0</sub> samples displayed a single rhombohedral Zn<sub>2</sub>SiO<sub>4</sub> phase, whereas Zn<sub>1.8</sub>SiO<sub>3.8</sub> specimens contained an additional Si‑rich glassy phase originated from excess SiO<sub>2</sub>. The Rietveld refinement and Raman results indicated that the crystal structure of the matrix was not sensitive to the dwell time. Therefore, the dielectric properties of the samples were predominantly determined by extrinsic factors. An extended sintering time enhanced densification of both compounds, and the Zn<sub>1.8</sub>SiO<sub>3.8</sub> ceramics exhibited higher relative density due to the formation of a liquid phase. Compared with conventional sintering, microwave processing enabled equivalent densification in a significantly shorter time. Furthermore, microwave-sintered ceramics possessed a refined grain structure, which was the primary factor responsible for enhanced <i>Q</i><sub>f</sub> values over conventionally sintered counterparts. However, Zn volatilization in Zn<sub>2.0</sub>SiO<sub>4.0</sub> ceramics persisted even at short dwell times, thereby limiting further performance improvements. Notably, Zn<sub>1.8</sub>SiO<sub>3.8</sub> ceramics sintered for 30&#xa0;min demonstrated outstanding dielectric properties (<i>ε</i><sub>r</sub> = 6.49, <i>Q</i><sub>f</sub> = 110,900&#xa0;GHz, <i>τ</i><sub>f</sub> =  − 22.5&#xa0;ppm/℃), making them a promising candidate for millimeter-wave communication applications.</p>

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Enhanced microstructure and dielectric properties of Zn2SiO4-based ceramics via microwave sintering

  • 期刊论文

  • 发表日期：

    2025年7月28日

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  • Junhao Yang,
  • Hao Li,
  • Rutie Liu,
  • Xiang Xiong,
  • Jie Chen

摘要

Microwave sintering was employed to rapidly fabricate high-performance zinc silicate ceramics, and the influence of sintering duration on the microstructure and dielectric properties of stoichiometric Zn2.0SiO4.0 and non-stoichiometric Zn1.8SiO3.8 was systematically investigated. The Zn2.0SiO4.0 samples displayed a single rhombohedral Zn2SiO4 phase, whereas Zn1.8SiO3.8 specimens contained an additional Si‑rich glassy phase originated from excess SiO2. The Rietveld refinement and Raman results indicated that the crystal structure of the matrix was not sensitive to the dwell time. Therefore, the dielectric properties of the samples were predominantly determined by extrinsic factors. An extended sintering time enhanced densification of both compounds, and the Zn1.8SiO3.8 ceramics exhibited higher relative density due to the formation of a liquid phase. Compared with conventional sintering, microwave processing enabled equivalent densification in a significantly shorter time. Furthermore, microwave-sintered ceramics possessed a refined grain structure, which was the primary factor responsible for enhanced Qf values over conventionally sintered counterparts. However, Zn volatilization in Zn2.0SiO4.0 ceramics persisted even at short dwell times, thereby limiting further performance improvements. Notably, Zn1.8SiO3.8 ceramics sintered for 30 min demonstrated outstanding dielectric properties (εr = 6.49, Qf = 110,900 GHz, τf =  − 22.5 ppm/℃), making them a promising candidate for millimeter-wave communication applications.