B位替代对Bi2(Zn1/3Nb2/3)O7陶瓷介电性能的影响
Effect of B Site Substitution on Dielectric Properties of Bi2(Zn1/3Nb2/3)O7 Based Ceramics
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摘要: 采用传统的二次球磨固相反应法制备了Bi2(Zn1/3Nb2/3-xMx)2O7(M为Sn,Zr,Ti)陶瓷,并使用X射线衍射仪、扫描电镜、介电性能测试仪等研究了Sn4+,Zr4+,Ti4+的B位替代对陶瓷烧结温度、物相、显微形貌以及介电性能的影响.结果表明:当替代量x≤0.25时,所得陶瓷均保持单一的单斜焦绿石相结构;Zr4+,Ti4+替代的陶瓷达到最致密的烧结温度与未经替代的一致,而Sn4+替代的陶瓷在1 020 ℃烧结才可以达到最致密;用Ti4+,Zr4+替代的陶瓷晶粒尺寸与基体的相当,而Sn4+替代的陶瓷晶粒尺寸大小不一;Sn4+,Zr4+替代的陶瓷介电常数温度系数随着替代量的增加逐渐减小,Sn4+替代的陶瓷在x=0.25时为负值,Ti4+替代的陶瓷介电常数温度系数随着替代量的增加先增大后减小,但始终为正值.Abstract: 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.