Low dielectric loss in vanadium-based zircon ceramics via high-entropy strategy
Yuheng Zhang, Huaicheng Xiang, Wu Xiaoyu, Yang Zhou, Ying Tang, Liang Fang
Abstract
Zircon ceramics have potential applications in next-generation wireless communication because of their low permittivity and adjustable temperature coefficient in microwave frequency. However, the vast challenge of realizing ultra-low dielectric loss still existed. Here, we propose a high-entropy strategy to enhance the bonding of the A-site dodecahedron in zircon and design (Nd<sub>0.2</sub>Eu<sub>0.2</sub>Y<sub>0.2</sub>Ho<sub>0.2</sub>Yb<sub>0.2</sub>)VO<sub>4</sub> ceramic with a high quality factor (high <em>Q×f</em>, that is,<em> </em>low dielectric loss). The (Nd<sub>0.2</sub>Eu<sub>0.2</sub>Y<sub>0.2</sub>Ho<sub>0.2</sub>Yb<sub>0.2</sub>)VO<sub>4</sub> high-entropy ceramic, which belongs to the tetragonal zircon structure with the <em>I</em>4<sub>1</sub>/<em>amd</em> space group, exhibits low permittivity (<em>ε<sub>r</sub></em> = 11.55), a negative temperature coefficient of resonant frequency (<em>τ<sub>f</sub></em> = -37.3 ppm/°C), and a high <em>Q×f </em>of 76,400 GHz (at 12.31 GHz). The high <em>Q×f</em> value can be attributed to the high chemical bond strength and structural stability. Furthermore, the relationship between the crystal structure and the microwave dielectric properties of (Nd<sub>0.2</sub>Eu<sub>0.2</sub>Y<sub>0.2</sub>Ho<sub>0.2</sub>Yb<sub>0.2</sub>)VO<sub>4</sub> high-entropy ceramic has been analyzed through the HR-TEM, Raman, far-infrared reflection spectrum, and chemical bond theory. This work provides an effective avenue to design microwave dielectric materials with low loss to meet the demanding applications of passive components.