A new temperature stable microwave dielectric ceramic with low-sintering temperature in Li2TiO3–Li2Zn3Ti4O12 system

Abstract The crystalline phases, microstructure, composition analysis and microwave dielectric properties of Li 2 TiO 3 – x  vol.% Li 2 Zn 3 Ti 4 O 12 ( x  = 15–40) composite ceramics with 1–3 wt.% Li 2 O–ZnO–B 2 O 3 (LZB) glass addition prepared by solid-state reaction method have been investigated. A near zero temperature coefficient of resonant frequency ( τ f ) of about −1.3 ppm/°C was obtained in the Li 2 TiO 3 –30 vol.% Li 2 Zn 3 Ti 4 O 12 ceramic sintered at 1100 °C for 2 h with permittivity of 22.0, Q  ×  f value of 38,900 GHz. The microwave dielectric properties of Li 2 TiO 3 –20 vol.% Li 2 Zn 3 Ti 4 O 12 ceramics with 1–3 wt.% LZB glass addition sintered at 900 °C for 2 h were characterized. The addition of 2.5 wt.% LZB glass reduced the sintering temperature of the Li 2 TiO 3 –20 vol.% Li 2 Zn 3 Ti 4 O 12 ceramic from 1100 °C to 900 °C without obvious degradation of the microwave dielectric properties. The 2.5 wt.% LZB glass-added Li 2 TiO 3 –20 vol.% Li 2 Zn 3 Ti 4 O 12 ceramic sintered at 900 °C for 2 h could reach a high relative density of 98% of the theoretical density of the Li 2 TiO 3 –20 vol.% Li 2 Zn 3 Ti 4 O 12 ceramic and exhibited microwave dielectric properties of ɛ r = 22.0, Q  ×  f  = 28,407 GHz, and a near zero τ f value of −1.6 ppm/°C. Moreover, this ceramic has a chemical compatibility with Ag electrode, making it a very promising candidate material for Low-temperature co-fired ceramic (LTCC) applications.