Phase evolution and microwave dielectric characteristics of Ti-substituted Mg2SO4 forsterite ceramics

In the present paper, the phase evolution and microstructures of Ti-substituted Mg2SiO4 forsterite ceramics with nominal composition Mg-2(Si1-xTix)O-4 were investigated together with their microwave dielectric characteristics. MgSiO3 secondary phase was observed in Mg2SiO4 ceramics, and it could be suppressed by Ti-substitution. However, Mg2TiO4 and MgTi2O5 appeared gradually with increasing Ti-substitution amount. The dielectric constant slightly increased from 6.8 to 8.1 with Ti-substitution, and the Qf value was improved significantly and reached the maximum at x=0.1 where the optimum combination of microwave dielectric characteristics were achieved: epsilon(r)=7.4, Qf=73,760 GHz at 15 GHz, tau(f)=60 ppm/degrees C. (c) 2007 Published by Elsevier B.V.