Effect of stress on microwave dielectric properties of layered Mg0.93Ca0.07TiO3–(Ca0.3Li0.14Sm0.42)TiO3 ceramics

Microwave dielectric properties were studied as a function of the number of dielectric layer for the layered functionally graded materials (FGMs) structure of Mg0.93Ca0.07TiO3 (MCT) and (Ca0.3Li0.14Sm0.42)TiO3 (CLST). Dielectric constants and temperature coefficients of resonant frequency (TCF) of the double- and triple-layered specimens were not changed significantly with a number of dielectric layers, but only depended on the net compositional ratio. However, quality factor (Qf) was affected by the thermal stress applied to the dielectric layers. For the specimens with same compositional ratios, Qf of triple-layered specimen had lower value than that of double-layered specimen, which was attributed to the increased thermal stresses to dielectric layers.