SrGa 12O 19: The first low- ε r Ga-based microwave dielectric ceramic with anomalous positive τ f

• DOI: 10.26599/jac.2024.9220947
• Publication Date: 2024-08-01T02:55:39Z
• Authors: Yang Yang; Weishuang Fang; Huixing Lin; Jie Li; Huaicheng Xiang; Ying Tang; Lei Li; Liang Fang
• Keywords: TP785-869; magnetoplumbite; rattling effect; Clay industries. Ceramics. Glass; microwave dielectric properties; chemical bond theory

Dielectric ceramics with low <em>ε_r</em>, high <em>Q</em>×<em>f</em>, and near-zero <em>τ_f</em> in the microwave bands are key materials used fifth/sixth-generation (5G/6G) telecommunication, while of most low-<em>ε_r</em> dielectric is relatively negative. In this work, first Ga-based ceramic SrGa₁₂O₁₉ anomalous positive was reported, cause <em>τ_f</em>, intrinsic polarization loss mechanism were systematically studied. According to XRD TEM, formed a pure hexagonal magnetoplumbite structure spinel block rock-salt stacking along crystallographic <em>c</em>-axis. When sintered at 1430 °C, it possessed optimal properties <em>ε_r</em> 14.46, <em>Q</em>×<em>f</em> 64,705 GHz, exceptional +55.7 ppm/°C, linear thermal expansion coefficient (<em>α_L</em>) 11.617 ppm/°C. The large deviation between <em>ε_r</em>_(C-M) 45.31% resulted from rattling effect atoms block. unique (+55.7 ppm/°C) governed by effect, resulting <em>τ_αm</em> 8.489 ppm/℃ negative <em>τ_ε</em> −132.864 ppm/℃. P-V-L chemical bond theory showed greater contribution <em>f_i</em> (52.95%), <em>ε </em>(55.15%),<em> E </em>(56.87%) <em>U </em>(74.88%) than those analyzed using infrared reflectivity spectra. favorable performances indicated novel compensator. This selection compounds different structural layer combinations provides new idea for exploring excellent ceramics.