Low dielectric loss in vanadium-based zircon ceramics via high-entropy strategy

Zircon ceramics have potential applications in next-generation wireless communication because of their low permittivity and adjustable temperature coefficient at microwave frequencies. However, the vast challenge of realizing ultralow dielectric loss still exists. Here, we propose a high-entropy strategy to enhance the bonding of the A-site dodecahedron in zircon and design (Nd 0.2 Eu 0.2 Y 0.2 Ho 0.2 Yb 0.2 )VO 4 ceramics with a high quality factor (high Q x f , that is, low dielectric loss). The (Nd 0.2 Eu 0.2 Y 0.2 Ho 0.2 Yb 0.2 )VO 4 high-entropy ceramics, which belong to the tetragonal zircon structure with the I 4 1 / amd space group, exhibit a low relative permittivity (epsilon r = 11.55), a negative temperature coefficient of resonant frequency (tau f= -37.3 ppm/degrees C), and a high Q x f of 76,400 GHz (at 12.31 GHz). The high Q x f 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 0.2 Eu 0.2 Y 0.2 Ho 0.2 Yb 0.2 )VO 4 high-entropy ceramics was analyzed through high resolution transmission electron microscopy (HRTEM), Raman spectroscopy, far-infrared reflection spectroscopy, and chemical bond theory. This work provides an effective avenue for designing microwave dielectric materials with low loss to meet the demands of passive components.