Structure and synergy performance of (1-x)Sr0.25Ce0.5TiO3-xLa(Mg0.5Ti0.5)O3 based microwave dielectric ceramics for 5G architecture

The crystal structure and microwave (MW) dielectric characteristics of the compound in the perovskite type series (1-x) (Sr0.25Ce0.5TiO3)-xLa(Mg0.5Ti0.5)O-3, x = 0.0 to 0.6 have been studied. The structural phase evolutions from orthorhombic (for x = 0.0) to cubic (for x >= 0.15) as a function of La(Mg0.5Ti0.5)O-3 have been investigated and are related to variation in the dielectric characteristics. For x = 0.0, the electron diffraction (TEM) revealed that Sr0.25Ce0.5TiO3 compound were tilted in both anti-phase and anti-parallel displacement of A-site cation. The nonlinear trend of the temperature coefficient of resonant frequency (tau(f)) vs dielectric constant resulted from the tilted (for x = 0.0) to nontilted (for x >= 0.15) structure transition. The value of tau(f) decreases markedly from +194 ppm/degrees C (x = 0.0) to + 0.8 ppm/degrees C (x = 0.6), but the Q x f value (Q-factor) increases from 19,238 GHz to 37,508 GHz. Low loss microwave (MW) dielectric properties: epsilon(r) = 47.0, Q x f = 37508 GHz and tau(f) = +15 ppm/degrees C and epsilon(r) = 39, Q x f = 34098 GHz and tau(f) = +0.8 ppm/degrees C were achieved for compositions with x = 0.45 and 0.6. (C) 2018 Elsevier B.V. All rights reserved.