(1-x)Ba(Mg_(1/3)Nb_(2/3))O_3-xBaSnO_3陶瓷的微波介电性能(英文)

MICROWAVE DIELECTRIC PROPERTIES OF (1-x)Ba(Mg_(1/3)Nb_(2/3))O_3-xBaSnO_3 CERAMICS

用传统陶瓷制备方法制备了(1-x)Ba(Mg1/3Nb2/3)O3-xBaSnO3[0.0≤x≤0.3,(1-x)BMN-xBS]体系微波介质陶瓷,研究了该陶瓷的微观结构和微波介电性能。用X射线衍射仪研究陶瓷的晶体结构。用扫描电镜观察陶瓷的显微结构。用网络分析仪测试陶瓷的微波介电性能。结果表明:晶格常数c和a均随x值的增加而增加;晶格常数比(c/a)随x值的增加而减小。当x≥0.1时,1:2有序衍射峰消失。陶瓷的平均晶粒尺寸在0.7～2μm之间。随x值的增加,陶瓷的相对介电常数(εr)和谐振频率温度系数(τf)呈线性减小;品质因数与谐振频率的乘积(Qf)呈非线性变化。当x=0.15时,Qf达到最大值,为86200GHz。当x=0.3时,在此体系中可以获得τf接近零的微波介质陶瓷Ba(Sn0.3Mg0.233Nb0.467)O3,其微波介电性能如下:εr=26.1;Qf=42500GHz;τf=4.3×10-6/℃。

The （1-x）Ba（Mg1/3Nb2/3）O3-xBaSnO3 （0.0≤x≤0.3, （1-x）BMN-xBS） ceramics were prepared by the conventional ceramics preparation technique. The microstructures and microwave dielectric properties of （1-x）BMN-xBS ceramics were investigated. X-ray diffraction was used to investigate the crystal structures of the ceramics. Scanning electron microscope was utilized to observe the microstructures of the ceramics. The microwave dielectric properties were measured using a network analyzer. The results show that the lattice constants of c and a both increase with the increase of x. However, the lattice constant ratio （c/a） decreases as x increases. The average grain size of the ceramics was in the range of 0.7-2 μm. The relative dielectric constant （εr） and resonance frequency temperature coefficient （τf ） value of the ceramics decrease linearly. However, the quality factor plus resonance frequency （Qf ） values vary non-linearly with composition. The highest Qf value achieved in this investigation was about 86 200 GHz, which occurred when x=0.15. A new microwave dielectric ceramic with near-zero τf in the （1-x）BMN-xBS system was attained when x=0.3. The Ba（Sn0.3Mg0.233Nb0.467）O3 solid solution ceramics exhibit good microwave properties：εr=26.1, Qf = 42 500 GHz and τf =4.3×10-6/ ℃ .