Srn+1TinO3n+1 (n=1, 2) microwave dielectric ceramics with medium dielectric constant and ultra-low dielectric loss

Srn+1TinO3n+1 (n=1, 2) ceramics with tetragonal Ruddlesden-Popper structure were prepared via a standard solid-state reaction process, and their microstructures and microwave dielectric properties were investigated systematically. The phase composition, grain morphology, and densification behavior were explored using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Outstanding microwave dielectric properties were achieved in the present ceramics: epsilon(r)=42, Qxf=145200GHz, (f)=130ppm/degrees C for Sr2TiO4, and epsilon(r)=63, Qxf=84 000GHz, (f)=293ppm/degrees C for Sr3Ti2O7, respectively. The present ceramics might be expected as excellent candidates for next-generation medium-permittivity microwave dielectric ceramics after the further optimization of (f) value.