Microwave dielectric properties of Mg2SiO4-Ca1-ySm2y/3TiO3 composite ceramics

In this work, (1-x)Mg2SiO4-xCa(1-y)Sm(2y/3)TiO(3) ceramics were fabricated using the conventional solid-state reaction method. When y = 0.2, the effects of Ca1-ySm2y/3TiO3 contents on microstructure, phase evolution, and microwave dielectric properties of the samples were studied. The X-ray diffraction showed that Mg2SiO4 and Ca0.8Sm0.4/3TiO3 co-existed in composite ceramics. The dielectric constant (epsilon(r)) and temperature coefficient of resonant frequency (tau(f)) increased with the increasing content of Ca0.8Sm0.4/3TiO3, while the quality factor (Q x f) decreased. At x = 0.22, the (1-x) Mg2SiO4-xCa(0.)(8)Sm(0.)(4/3)TiO(3) ceramics sintered at 1325 degrees C for 3 h possessed optimal microwave dielectric properties: epsilon(r) similar to 11.89, Q x f value similar to 32,703 GHz and tau(f) + 0.49 ppm/degrees C. As a result, the epsilon(r) of (1-x) Mg2SiO4 + xCa(1-ys)m(2y/3)TiO(3) ceramics could be adjusted in the range of 10.83 to 13.88 while the tau(f) is near-zero.