Improving the microwave dielectric properties of Ga2[LiGa3]O8 inverse spinel by enhancing B-site ordering degree

作者：Fang, Weishuang; Ao, Laiyuan; Tang, Ying; Li, Jie^*; Sun, Yihua; Fang, Liang

来源：Ceramics International, 2022, 48(1): 896-902.

DOI：10.1016/j.ceramint.2021.09.173

• Ga-2[Li1+xGa3]O8+delta
• Li-excess
• Inverse spinel
• Structural order

A series of inverse spinel ceramics, Ga-2 [Li1+xGa3]O8+delta (0.05 = x <= 0.125), were synthesized by the conventional solid-phase reaction. The addition of Li (x <= 0.1) increased the order degree of octahedra cations and caused an expansion in cell volume, and the maximum solution was located at 0.1-0.125. The dielectric constant of Ga-2 [Li1+xGa3]O8+delta ceramics increased with the ionic polarizability of primitive unit cell, and the optimum microwave dielectric performances were obtained at x = 0.1 sample sintered at 1260 degrees C with epsilon(r) = 10.78 +/- 0.1, Q x f = 171,171 +/- 500 GHz, and tau(f) =-56.47 +/- 1.0 ppm/degrees C. The if showed an opposite variation trend to that of the Ga1 bond valence and octahedron distortion. The Q x f was determined by the packing fraction and FWHM of 424 cm(-1) Raman mode. In addition, the intrinsic dielectric properties of Ga-2 [Li1+xGa3]O8+delta ceramics were evaluated by infrared reflectivity spectra. The results show that Ga-2 [Li1+xGa3]O8+delta ceramic is a promising substrate material.

• 单位
  广西大学; 桂林理工大学