Abstract:
The Sr–Gehlenite (Sr2Al2SiO7) ceramic has been prepared by the conventional solid-state ceramic route.Phase pure Sr2Al2SiO7 (SAS) ceramic sintered at 1525 ◦C for 4 h has εr = 7.2 and Qu × f = 33,000 GHz. The SAS showed large negative f of
−37.0 ppm/ ◦C. A low value of f was achieved by preparing SAS–CaTiO3 composite. The composite with 0.04 volume fractions (Vf) CaTiO3 sintered at 1500 ◦C for 4 h showed good microwave dielectric properties: εr = 8.6, Qu × f = 20,400 GHz and f = +8.5 ppm/◦C
