Microwave dielectric properties of La ₃Ti ₂TaO ₁₁ ceramics with perovskite-like layered structure

The first characterization of the microwave dielectric properties of the La ₃Ti ₂TaO ₁₁ ceramics is presented. An ordinarily sintered ceramic at 1560°C exhibits good microwave dielectric properties with e{open} _r=46, Q×f=7500GHz and τ _f=-47ppm/°C. An alternative approach to tailor the temperature coefficient of resonate frequency of La ₃Ti ₂TaO ₁₁ ceramics is also presented. Textured La ₃Ti ₂TaO ₁₁ ceramics were fabricated using spark plasma sintering (SPS). By controlling the sintering temperature, orientation degree increased together with the steadily increase in e{open} _r and Q×f. A noteworthy change in τ _f from -43.1ppm/°C to -13.6ppm/°C with increasing orientation degree was observed. These results suggest that grain-orientation control was an effective way to tailor the microwave dielectric properties of La ₃Ti ₂TaO ₁₁ ceramics.