Temperature-stable and medium-high K of Ti/W co-doped M-phase LNT microwave ceramics for LTCC dielectric devices

The increasing demand for miniaturized electronic devices requires the development of advanced medium-high K materials. In this work, novel (Ti 1/2 W 1/2 ) 5+ -substituted LiNb 0.6- x (Ti 1/2 W 1/2 ) x Ti 0.5 O 3 (LNT- x TW, 0 ≤  x  ≤ 0.12) ceramics were successfully prepared by the solid-state method. The increase in TW content led to the formation of LNT-0.08 TW ceramic with medium-high K and high Q ×  f after sintering at 1050 °C. This ceramic also recorded improved characteristics with ε r ∼53.84, Q ×  f ∼7482 GHz and τ f ∼43.43 ppm/°C related to ionic polarizability, large grains, high densification, and [Ti 2 O 3 ] 2+ / N layers. In addition, Li 2 O–B 2 O 3 –SiO 2 –CaO–Al 2 O 3 (LBSCA) used as an effective sintering aid, improved densification and promoted sintering by not only decreasing the temperature to 900 °C, but also enhancing the microwave dielectric properties with ε r ∼49.46, Q ×  f ∼8149 GHz, and τ f ∼12.04 ppm/°C. The Q ×  f value was estimated to 1.15 ∼ 2-fold higher than other LNT-based ceramics within stable τ f . More encouragingly, the LNT-0.08 TW ceramic also showed good chemical match with Ag, suggesting usefulness for miniaturized LTCC devices.