Microwave dielectric properties of rutile (Zn1/3Nb2/3)0.40(Ti1−xSnx)0.60O2 (0.15 ≤ x ≤ 0.30) ceramics

Microwave dielectric properties of (Zn1/3Nb2/3)0.40(Ti1−xSnx)0.60O2 ceramics were investigated as a function of SnO2 content (0.15 ≤ x ≤ 0.30). A single phase with tetragonal rutile structure was obtained through the entire composition. The unit-cell volume of the specimens was increased with SnO2 content, due to the larger ionic radius of Sn4+ (0.69 Å) than that of Ti4+ (0.605 Å) for octahedral site. Dielectric constant (K) of the sintered specimens was affected by the dielectric polarizability. Quality factor (Qf) was dependent on the degree of reduction of Ti4+ ion. With an increase of SnO2 content, the temperature coefficient of resonant frequency (TCF) of the specimens decreased due to the decrease of the octahedral distortion of rutile structure.