Medium K and temperature-stable Co2+-substituted LiNb0.6Ti0.5O3 microwave dielectric ceramics for LTCC miniaturized applications.

At present, 5 G communication is developing rapidly, devices are becoming miniaturized, which requires the continuous emergence of materials with high dielectric constant. In this work, choosing Co2+ to substitute Li 1–2 x Co x Nb 0.6 Ti 0.5 O 3 (LCNT, 0 ≤ x ≤ 0.1) + 0.4 wt % LBSCA ceramics successfully achieved high permittivity ε r and temperature stable resonant temperature frequency coefficient τ f sintered at 950 ℃, including ε r ∼62, Q× f ∼6255 GHz, and τ f ∼0.97 ppm/℃ (x = 0.02), ε r ∼56.55, Q× f ∼7090 GHz, and τ f ∼− 28.07 ppm/℃ (x = 0.06). Meanwhile, the influence of Co2+ on LNT ceramics for phase composition, micro-structure, microwave dielectric performance and Raman vibration had been studied in detail. All samples belonged to M phase. Rod-like or blocky grains were gradually refined, indicating that Co2+ had the effect of grain refinement. In microwave dielectric performance, ionic polarizability played a leading role in ε r , Q× f value was positively correlated with the bulk density, τ f directly depended on the average repeatable layer N. In Raman spectroscopy, three modes of Raman vibration had been identified as translation or rotation of Li+ ions, Nb/Ti bond vibration, [Nb/TiO 6 ] octahedral vibration. To meet low temperature co-fired applications, the LCNT (x = 0.02) ceramic didn't react with Ag, which suggested it was achieving candidates for the next generation of medium K LTCC materials. • Adapting Co2+ ions control engineering + adding 0.4w t % LBSCA to realizing LTCC technology within the LCNT ceramics. • LC 0.06 NT ceramic maintained a high K and quality factor: ε r ~56.55, Q× f ~7090 GHz, τ f ~-28.07 ppm/℃ sintering at 950℃. • The enhanced microwave properties were attributed to the higher bulk density, and average repeatable layers N. [ABSTRACT FROM AUTHOR]