A comprehensive study on low temperature sintering and microwave/terahertz dielectric properties of BaO-P2O5 binary ceramics

Abstract

In this paper, the sintering characteristics, microstructure, phase composition, crystal structure, dielectric properties, and thermal properties of ceramic samples in BaO-P2O5 binary system are comprehensively investigated. Furthermore, the intrinsic dielectric properties of ceramic samples in BaO-P2O5 binary system were elucidated through the analysis of far-infrared (FIR) reflectance spectra and terahertz time-domain spectra (THz-TDS). Experimental results show that BaP2O6 ceramics exhibited good microwave dielectric properties after sintering at 800 °C for 2 h: permittivity (εr) = 6.3, quality factor (Q×f) = 17,100 GHz (@ 12.75 GHz), and τf (TCF, temperature coefficient of resonant frequency) = − 45 ppm/°C. Ba3P2O8 + 2 wt. % BCB ceramics exhibited excellent microwave dielectric properties after sintering at 800 °C for 2 h: εr = 10.1, Q×f = 75,000 GHz (@ 11.05 GHz), and τf = + 9 ppm/°C, meanwhile exhibited good chemical compatibility with Ag and Cu electrodes. A cylindrical dielectric resonant antenna (DRA) element was designed based on Ba3P2O8 + 2 wt. % BCB ceramics and a 1 × 4 line array was designed based on the unit antenna model. The 1 × 4 DRA line array exhibited high radiation efficiency of 95 %, accompanied by a realized gain of 9.5 dBi. The utilization of Ba3P2O8 + 2 wt. % BCB ceramics is anticipated for 5.8 GHz Wi-Fi communication. This work presents a comprehensive theoretical framework and technical guidance for the development of ceramics in the BaO-P2O5 binary system.