Crystal structure and microwave dielectric properties of a new A4B3O12-type cation-deficient perovskite Ba3LaTa3O12

A new microwave dielectric ceramic Ba3LaTa3O12 has been prepared by conventional solid-state ceramic route. Through Rietveld refinement of X-ray powder diffraction data, the compound is identified as an A4B3O12-type B-site cation-deficient perovskite with space group R3¯m and lattice constants a = 5.7573(2) Å, c = 28.2386(2) Å, V = 810.62(4) Å3 and Z = 3. The microwave dielectric properties of Ba3LaTa3O12 were investigated. The compound exhibits a relative dielectric constant (ɛr) of 36.8, a quality factor Qu × f of 21,965 at 6.4040 GHz and a small negative temperature coefficient of resonant frequency (τf) of −49.6 ppm/°C.