TY - JOUR
T1 - Dielectric properties and mixture behavior of Mg4Nb2O9-SrTiO3 ceramic system at microwave frequency
AU - Huang, Cheng Liang
AU - Chen, Jhih Yong
AU - Liang, Chih Chao
N1 - Funding Information:
This work was supported by the National Science Council of Taiwan under grant NSC 96-2221-E-006-117.
PY - 2009/6/10
Y1 - 2009/6/10
N2 - The microwave dielectric properties and the microstructures of the (1 - x)Mg4Nb2O9-xSrTiO3 ceramic system prepared by the conventional solid-state route were investigated. SrTiO3 was employed as a τf compensator and was added to Mg4Nb2O9 to achieve a temperature-stable material. Corundum-structured Mg4Nb2O9 and perovskite-structured SrTiO3 were coexisted and the two-phase system was confirmed by the XRD and EDX analysis. Dielectric properties are correlated to the sintering temperature and the compositional ratio of the specimens. Although the εr of the specimen could be boosted by increasing amount of SrTiO3, it would instead render a decrease in the Q × f. The τf value is strongly correlated to the compositions and can be controlled through the existing phases. In fact, τf could be adjusted to near-zero by mixing 60 mole% Mg4Nb2O9 and 40 mole% SrTiO3. A dielectric constant (εr) of 21.02, a high Q × f value of 112,000 GHz (measured at 9.7 GHz) and a temperature coefficient of resonant frequency (τf) of 1.6 ppm/°C were obtained for 0.6Mg4Nb2O9-0.4SrTiO3 sintered at 1300 °C for 4 h. It is proposed as a very promising dielectric material for low-loss microwave and millimeter wave applications.
AB - The microwave dielectric properties and the microstructures of the (1 - x)Mg4Nb2O9-xSrTiO3 ceramic system prepared by the conventional solid-state route were investigated. SrTiO3 was employed as a τf compensator and was added to Mg4Nb2O9 to achieve a temperature-stable material. Corundum-structured Mg4Nb2O9 and perovskite-structured SrTiO3 were coexisted and the two-phase system was confirmed by the XRD and EDX analysis. Dielectric properties are correlated to the sintering temperature and the compositional ratio of the specimens. Although the εr of the specimen could be boosted by increasing amount of SrTiO3, it would instead render a decrease in the Q × f. The τf value is strongly correlated to the compositions and can be controlled through the existing phases. In fact, τf could be adjusted to near-zero by mixing 60 mole% Mg4Nb2O9 and 40 mole% SrTiO3. A dielectric constant (εr) of 21.02, a high Q × f value of 112,000 GHz (measured at 9.7 GHz) and a temperature coefficient of resonant frequency (τf) of 1.6 ppm/°C were obtained for 0.6Mg4Nb2O9-0.4SrTiO3 sintered at 1300 °C for 4 h. It is proposed as a very promising dielectric material for low-loss microwave and millimeter wave applications.
UR - https://www.scopus.com/pages/publications/67349215283
UR - https://www.scopus.com/pages/publications/67349215283#tab=citedBy
U2 - 10.1016/j.jallcom.2008.11.089
DO - 10.1016/j.jallcom.2008.11.089
M3 - Article
AN - SCOPUS:67349215283
SN - 0925-8388
VL - 478
SP - 554
EP - 558
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
IS - 1-2
ER -