Microwave dielectric properties of SrLa[Ga1-x(Mg0.5Ti0.5)x]O4 and SrLa[Ga1-x(Zn0.5Ti0.5)x]O4 (x=0.2-0.8) ceramics

SrLa[Ga1-x(R0.5Ti0.5)(x)]O-4 (R = Mg, Zn) ceramics were prepared by a standard solid state sintering method. The single-phase ceramics with K2NiF4-type layered perovskite structure and I4/mmm space group were obtained, indicating that SrLa(R0.5Ti0.5) and SrLaGaO4 can form the unlimited solid solutions. With increasing x for R = Mg and Zn, epsilon(r) increases monotonously, the Qf value first increases and then decreases, while tau(f) increases from a negative to a positive value. The optimized microwave dielectric properties were obtained as following: epsilon(r) = 23.3, Qf = 89 400 GHz, tau(f) = -0.8 ppm/degrees C for SrLa[Ga-0.6(Mg0.5Ti0.5)(0.4)]O-4 and epsilon(r) = 23.3, Qf = 76 200 GHz, tau(f) = 0.2 ppm/degrees C for SrLa[Ga-0.7(Zn0.5Ti0.5)(0.3)]O-4, indicating that the present solid solution ceramics are the promising candidates as microwave resonator materials for the telecommunication applications.