Synthesis and characterization of low-thermal-budget ilmenite-type [(Mg1-x Mnx)0.95Zn0.05]TiO3 (x = 0–0.4) microwave dielectrics for high-frequency applications

Abstract

This paper researches ilmenite-type [(Mg_1-xMn_x)_0.95Zn_0.05]TiO₃ dielectrics synthesized by the solid-state reaction method and the influence of Mg²⁺ by Mn²⁺ on the physical characterization, such as microstructure, crystallization, Raman spectra, and microwave dielectric properties, was investigated systematically. The microstructures and phases of the synthesized dielectrics were meticulously analyzed using EDS, SEM, XRD, XPS, and Raman spectroscopy. Optimization of the process conditions revealed that sintering temperature and time significantly impact the microwave dielectric properties, and further tuning Mn²⁺ doping concentration x can obtain the wide-range quality factor. The optimal dielectric properties for [(Mg_0.8Mn_0.2)_0.95Zn_0.05]TiO₃ were achieved when sintered at 1250 °C for 3 h, including a permittivity (ε_r) of approximately 17.4, a quality factor (Qf) of around 180,000 GHz, and a temperature coefficient of resonance frequency (τ_f) of about − 58 ppm/°C. Due to its substantially reduced thermal budget and low-loss microwave dielectric properties, the proposed dielectrics demonstrate a high potential for applications in manufacturing high-quality substrates for high-frequency devices in 5G and beyond 5G communication systems.