Abstract
The reaction sequence of 0.15(Ba 0.95 Sr 0.05 )O·0.15Sm 2 O 3 ·0.7TiO 2 ceramics during heating as well as the effects of calcination and sintering on microwave properties were investigated. Quantitative microscopic analysis was performed to obtain the volume fraction of the phases. It was found that the amount of second phase, especially TiO 2 (rutile), greatly affected the temperature coefficient of resonant frequency of the ceramics. By varying calcination and/or sintering temperature, the temperature coefficient of resonant frequency could be adjusted to nearly zero.