Microwave Dielectric Properties of Ba3.75Nd9.5Ti18O54 Ceramic by the (Co1/3Nb2/3)4+ Substitution

Abstract

To improve the microwave dielectric properties of the Ba3.75Nd9.5Ti18O54 ceramic, the (Co1/3Nb2/3)4+ substitution for titanium is performed. When 0 ≤ z ≤ 1, the system keeps a single phase. The decreasing relative density causes the dielectric constant to decrease. The quality factor (Q×f) value increases by 13 %, which is because of the growing grain size. The temperature coefficient of resonant frequency successfully decreases by 70 % and is related to the tolerance factor. For 1.5 ≤ z ≤ 2, the secondary phase appears and the microwave dielectric properties are degraded rapidly. In addition, the solid solution limit of the Ba3.75Nd9.5Ti18O54 ceramic is found 1 < z < 1.5 when the (Co1/3Nb2/3)4+ substitution is performed.