Microstructure and Dielectric Properties of (Ba, Ta) Co-Doped Sr2Nb2O7 Ceramics

(Sr1-xBax) 2(Nb0.9Ta0.1) 2O7 (SBNT) ceramics were prepared by solid state reaction. The crystal structure of SBNT ceramics, surface morphology and dielectric properties were studied using XRD, SEM and LCR instrument analyzer, respectively. The results show that the grain size decreases with increasing Ba concentration, and all samples show single phase, no second phase can been observed. Addition of Ba ion can improve the dielectric properties of SBN ceramics. The dielectric constant increases first, then decreases; the maximum value (εr=97) can be obtained at x=0.1, the dielectric constant changes slightly with increasing wide frequency.