Abstract:
Alkaline earth orthosilicates M2SiO4 (Sr, Ca) ceramics were prepared by solid state ceramic route and their microwave dielectric properties were investigated. M2SiO4 ceramics have epsilon(r) in the range 8.5-13. At microwave frequencies, the Q (u) x f obtained were 17,900 GHz, 19,100 GHz and 26,100 GHz for Ba2SiO4, Sr2SiO4 and Ca2SiO4 respectively. The T-f of Ba2SiO4 was - 17 ppm/degrees C, whereas Sr2SiO4 and Ca2SiO4 exhibited high values of T-f, - 205 ppm/degrees C and - 89 ppm/degrees C respectively. The coefficient of thermal expansion (alpha (1)) of the orthosilicates was also studied.
