Effects of composition tailoring on structure and microwave dielectric characteristics of SrSmAlO4 ceramics

Abstract Effects of composition tailoring on the microwave dielectric characteristics of SrSmAlO 4 ceramics were investigated together with the structure. K 2 NiF 4 -type major phase with minor amount of secondary phases was observed in the modified ceramics with nominal composition Sr 1+ x Sm 1− x AlO 4− x /2 ( x  = −0.05, −0.025, 0.025, 0.05), and the type of secondary phase is dependent on x . Sr 2.25 Sm 0.75 AlO 4.875 secondary phase is detected for x  > 0, while the secondary phase for x 2 Al 2 O 7 . Though the accurate stoichiometric composition is very important to guarantee the highest Qf value, it is an effective way to adjust the temperature coefficient of resonant frequency τ f by tailoring composition. τ f can be adjusted from negative to positive by varying x from 0 to −0.05, while more negative τ f can be achieved by varying x from 0 to 0.05. Suitable modified composition with x Qf value and small τ f with the controlled sensitivity to sintering temperature.