Ba2La2TiNb2O12: A new microwave dielectric of A4B3O12-type cation-deficient perovskites

A new A₄B₃O₁₂-type cation-deficient perovskite Ba₂La₂TiNb₂O₁₂ was prepared by the conventional solid-state reaction route. The phase and structure of the ceramics were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM). The compound crystallizes in the trigonal system with unit cell parameter a = 5.6726(3) Å, c = 27.740(2) Å, V = 773.04(9) ų and Z = 3. The microwave dielectric properties of the ceramic were studied using a network analyzer, and it shows a high dielectric constant of 42.70, a high quality factor with Q × f of 31,130 GHz, and a small negative τ_f of − 4.2 ppm °C^− 1.