Scholarlink

<p>In this work, two novel Ba-contained Y<sub>2</sub>BaM<sub>4</sub>SiO<sub>12</sub> (M = Al, Ga) ceramics with garnet structured were obtained by a solid-state reaction method. XRD patterns combined with Rietveld refinement analysis demonstrated that Y<sub>2</sub>BaAl<sub>4</sub>SiO<sub>12</sub> was formed a single cubic structure phase with an <i>Ia-</i>3<i>d</i> space group. While in the Y<sub>2</sub>BaGa<sub>4</sub>SiO<sub>12</sub> ceramics, apart from the main phase of garnet structure, a trace of peaks of SiO<sub>2</sub> were also detected. The bond valence and P–V–L chemical bond theory analysis results indicated that both of Ba cations presents a strength compressed effect in the Y<sub>2</sub>BaM<sub>4</sub>SiO<sub>12</sub> (M = Al, Ga) ceramics. And the large lattice energy of Al-O bonds might be the main reason for the Y<sub>2</sub>BaAl<sub>4</sub>SiO<sub>12</sub> formation of a stable garnet crystal structure without secondary phase and high <i>Q</i> × <i>f</i> values. The Y<sub>2</sub>BaGa<sub>4</sub>SiO<sub>12</sub> ceramics with a low relative density (91%) and microwave dielectric properties of <i>ε</i><sub><i>r</i></sub> = 12.6, <i>Q</i> × <i>f</i> = 4,530&#xa0;GHz, and <i>τ</i><sub><i>f</i></sub> = −&#xa0;28.6&#xa0;ppm/°C. The dense Y<sub>2</sub>BaAl<sub>4</sub>SiO<sub>12</sub> ceramics (relative density of 96.2%) with microwave dielectric properties of <i>ε</i><sub><i>r</i></sub> = 10.3, <i>Q</i> × <i>f</i> = 8,700&#xa0;GHz, and <i>τ</i><sub><i>f</i></sub> = −&#xa0;20.3&#xa0;ppm/°C was obtained at 1360&#xa0;°C for 4&#xa0;h. In the garnet structure, all the results demonstrates that the mismatch among the A-sites or C-sites cations will result in a low-fired temperature and severely deteriorated <i>Q</i> × <i>f</i> values.</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

Phase composition and microwave dielectric properties of two garnet structured Y2BaM4SiO12 (M = Al, Ga) ceramics with large size Ba cations on A-site

  • 期刊论文

  • 发表日期：

    2025年4月2日

查看全文
  • Junqi Chen,
  • Haotian Xie,
  • Zhaohui Wang,
  • Jingjing An,
  • Peilin Qing,
  • Jinwu Chen

摘要

In this work, two novel Ba-contained Y2BaM4SiO12 (M = Al, Ga) ceramics with garnet structured were obtained by a solid-state reaction method. XRD patterns combined with Rietveld refinement analysis demonstrated that Y2BaAl4SiO12 was formed a single cubic structure phase with an Ia-3d space group. While in the Y2BaGa4SiO12 ceramics, apart from the main phase of garnet structure, a trace of peaks of SiO2 were also detected. The bond valence and P–V–L chemical bond theory analysis results indicated that both of Ba cations presents a strength compressed effect in the Y2BaM4SiO12 (M = Al, Ga) ceramics. And the large lattice energy of Al-O bonds might be the main reason for the Y2BaAl4SiO12 formation of a stable garnet crystal structure without secondary phase and high Q × f values. The Y2BaGa4SiO12 ceramics with a low relative density (91%) and microwave dielectric properties of εr = 12.6, Q × f = 4,530 GHz, and τf = − 28.6 ppm/°C. The dense Y2BaAl4SiO12 ceramics (relative density of 96.2%) with microwave dielectric properties of εr = 10.3, Q × f = 8,700 GHz, and τf = − 20.3 ppm/°C was obtained at 1360 °C for 4 h. In the garnet structure, all the results demonstrates that the mismatch among the A-sites or C-sites cations will result in a low-fired temperature and severely deteriorated Q × f values.