La_2O_3对ZnO-Bi_2O_3-B_2O_3系统玻璃结构和介电性能的影响

Effects of La_2O_3 on Structure and Dielectric Characteristics of ZnO-Bi_2O_3-B_2O_3 Glass

采用烧结法制备添加La2O3的ZnO-Bi2O3-B2O3系统（以下简称ZBB系统）微晶玻璃,借助傅立叶变换红外光谱仪（FTIR）、拉曼光谱分析仪、X射线衍射（XRD）、热膨胀仪（DIL）和惠普自动电桥（LCR）首次研究添加La2O3对ZBB系统玻璃结构、微晶化、热膨胀系数（α）以及介电损耗（tan δ）和介电常数（εr）的影响.结果表明：添加量在0～2.0wt.％范围内,La2O3可以较显著的延缓该系统玻璃的析晶,并显著降低tan δ和εr;随着LaO3加入量的增加,α呈现先减小再增大后减小的趋势,并可能促使Bi2O3更多的进入玻璃结构中,[BiO3]、[BiO6]和孤立硼基团数量均呈现先增大后减小的趋势,当La2O3含量为1.5wt.％时基团数量达到最大,且此时α出现极大值.

Glass-ceramics of ZnO-Bi2O3-B2O3 system doped with La2O3 were prepared by sintering method and were characterized by Fourier transform infrared spectroscopy （FTIR）,Raman spectrum analyzer,X-ray diffractometry （XRD）,dilatometer （DIL） and HP automatic bridge （LCR）.The relationships the content of La2O3 with the structure,crystallization,thermal expansion coefficient （α）,dielectric constant （εr）,and dielectric loss （tanδ） of the glass ceramics are investigated.The results show that doping 0～2.0 wt.％ La2O3 can significantly inhibit crystallization,decrease εr and tanδ.La2O3 addition can significantly help Bi2O3 enter the network structure.with the La2O3 addition increasing,the α of the glass changes like the letter ＂N＂; the number of [BiO3],[BiO6] and isolated triangular orthoborate units firstly increases and then slightly decreases.When the content of La2O3=1.5 wt.％,the number of these units and the α reach their maximum.