Phase, Microstructure, and Microwave Dielectric Properties of (Mg0.95Co0.05)(Ti1−xSnx)O3 (0.05 ≤ x ≤ 0.20) Ceramics

Abstract

Phase, microstructure, and microwave dielectric properties of (Mg0.95Co0.05)(Ti1−xSnx)O3 (0.05 ≤ x ≤ 0.20) ceramics prepared via the conventional solid-state route were investigated. X-ray diffraction analysis showed the existence of a single phase for the compositions with Sn4+ ≤ 0.15; however, a further increase in Sn4+ caused the formation of a secondary SnO2 phase in the ceramics. The maximum observed densities of the single phase ceramics were higher than 95% of the theoretical density. An increase in the lattice parameters of the ceramics were observed with an increasing Sn4+ content. Dense microstructures were observed for the single phase ceramics at a sintering temperature of 1400°C, whereas a porous microstructure was observed for the ceramics with secondary phase. The unloaded quality factor (Qufo) of the ceramics was found to increase initially with an enhancing Sn4+ content from 0.05 up to 0.15; however, a sudden downfall was detected with a further enhancement in Sn4+. The dielectric constant and temperature coefficient of resonant frequency of the ceramics were observed to decline monotonically with enhancing Sn4+ content.