Compositional modulation in ZnGa2O4 via Zn2+/Ge4+ co-doping to simultaneously lower sintering temperature and improve microwave dielectric properties

• 作者: Ying XIONG Hongyuan XIE Zhenggang RAO Laijun LIU Zhengfeng WANG Chunchun LI
• 来源期刊: 先进陶瓷（英文版）
• 年，卷（期）: 2021,（6）
• 所属期刊栏目: Research Article
• 页码范围: 1360-1370
• 页数: 11页
• 语种: 英文

摘要

AB2O4-type spinels with low relative permittivity (εr) and high quality factor (Q× f) are crucial to high-speed signal propagation systems. In this work, Zn2+/Ge4+ co-doping to substitute Ga3+ in ZnGa2O4 was designed to lower the sintering temperature and adjust the thermal stability of resonance frequency simultaneously. Zn1+xGa2?2xGexO4 (0.1≤x≤ 0.5) ceramics were synthesised by the conventional solid-state method. Zn2+/Ge4+ co-substitution induced minimal variation in the macroscopical spinel structure, which effectively lowered the sintering temperature from 1385 to 1250℃. All compositions crystallized in a normal spinel structure and exhibited dense microstructures and excellent microwave dielectric properties. The compositional dependent quality factor was related to the microstructural variation, being confirmed by Raman features. A composition withx = 0.3 shows the best dielectric properties withεr≈ 10.09,Q× f≈ 112,700 THz, andτf≈?75.6 ppm/℃. The negativeτf value was further adjusted to be near-zero through the formation of composite ceramics with TiO2.