Effect of B Site Substitution on Dielectric Properties of Bi₂(Zn_1/3Nb_2/3)O₇ Based Ceramics

The Bi2(Zn1/3Nb2/3-xMx)2O7 (M was Sn,Zr,Ti) ceramics were prepared by traditional second solid phase reaction method. The effect of B site substitution of Sn4+,Ti4+,Zr4+ on the sintering temperature,microstructure and dielectric properties was investigated by means of XRD,SEM and dielectric property testing analyzer. The results show that the ceramic kept single monoclinic pyrochlore phase when Sn4+,Zr4+ and Ti4+ substitution content was no more than 0.25. The sintering temperature for the density ceramics substituted with Zr4+ and Ti4+ was both 1 000 ℃,but it was 1 020 ℃ for them substituted with Sn4+. The temperature coefficient of dielectric constant decreased gradually with the increase of substitution content of Sn4+,Zr4+. While it increased firstly and then decreased with the increase of substitution content,and its value was always positive.