Ba ₄ LiNb _{3− <i>x</i>} Ta _<i>x</i> O ₁₂ ( <i>x</i> =0–3): A Series of High‐Q Microwave Dielectrics from the Twinned 8H Hexagonal Perovskites

Abstract

A series of the twinned 8H hexagonal perovskites in the Ba 4 LiNb 3− x Ta x O 12 ( x =0–3) system were synthesized by the conventional solid‐state reaction method. Ba 4 LiNb 3− x Ta x O 12 solid solutions were single phase in the whole range of x values. The ceramics exhibit perfect microwave dielectric properties with relative permittivity, ɛ r ∼28–37, high quality factor, Q × f ∼37 000–104 000 GHz, and temperature coefficient of resonant frequency, τ f ∼+25–+65 ppm/°C.