Effect of Sn~(4+) B-Site Substitution on the Microstructure and Dielectric Properties of Ba(Mg_(1/3)Ta_(2/3))O_3 Microwave Ceramics

1.IntroductionRecent progress of microwave telecommunication de-mands the development and application of a variety ofmicrowave dielectric materials.The materials with highdielectric constant(ε),high quality factor(Q)and smalltemperature coefficient of resonant frequency(TCF)haveattracted the greatest interest of researchers.The com-pounds Ba(B'1/3B"2/3)O3(B'=Mg,Zn,Ni,etc.B"=Ta,Nb,etc.)with complex perovskite structure exhibit veryhigh Q value at microwave frequencies greaterthan10GHz.…

Effect of Sn4+ B-Site Substitution on the Microstructure and Dielectric Properties of Ba(Mg1/3Ta2/3)O3 Microwave Ceramics

The effect of Sn4+ (BaSnO3) B-site substitution on the microstructure and dielectric properties of Ba(Mg1/3Ta2/3O3 microwave ceramics was investigated. X-ray diffraction shows that a complex perovskite material Ba(Mg1/3Ta2/3)O3 was prepared. As Sn4+ content x increases in the (1-x) Ba(Mg1/3Ta2/3)O3-xBaSnO3 (x=0.00～0.20) system, the dielectric constant generally keeps unchanged, while TCF changes from positive to negative. Although the addition of Sn4+ reduces the ordering degree, Qf0 is still increased when the ceramics density increases. This trend implies that Qf0 of this system is mostly determined by ceramics density rather than ordering degree. After sintering at 1500℃ for 3 h, the system with x=0.15 was found to have excellent dielectric properties as follows: ε≈25, Qf0≥300,000 GHz at 7 GHz, TCF=-0.6×10-6℃.