Low-temperature sintered Li2.75MgTiO4F0.75 ceramics with enhanced temperature stability for LTCC applications

This study investigates the effects of TiO 2 doping on the temperature stability and dielectric properties of Li 2.75 MgTiO 4 F 0.75 ceramics for low-temperature co-fired ceramic (LTCC) applications. Li 2.75 MgTiO 4 F 0.75 - x TiO 2 (1 wt% ≤ x  ≤ 6 wt%) ceramics were synthesized via solid-state reaction. Among the compositions studied, the sample doped with 5 wt% TiO 2 and sintered at 850 °C exhibited optimal dielectric properties, including a ε r of 16.22, a Q × f of 79,195 GHz at 10.7 GHz, and a near-zero temperature coefficient ( τ f = −7.83 ppm/°C). Analysis revealed that LiF, which did not form part of a solid solution, aided densification and improved dielectric properties. However, the high dielectric loss of TiO 2 led to a decrease in the Q × f value. Terahertz frequency measurements further confirmed the system’s potential for terahertz communication applications, with ε r ≤ 13.7 and a tan δ between 0.01 and 0.1. Additionally, the ceramics demonstrated good chemical compatibility with Ag electrodes. These results highlight the promising application of Li 2.75 MgTiO 4 F 0.75 -5 wt%TiO 2 composite ceramics in LTCC technology.