【摘要】 采用普通陶瓷工艺制备了0.4Ba0.6Sr0.4TiO3-0.6MgO-xSiO2(0≤x≤5.0%)陶瓷,研究了SiO2含量对所制BST-MgO(BSTM)陶瓷微观结构以及低频、微波介电性能的影响。XRD分析表明,随着掺杂量的增加,SiO2在BSTM陶瓷中首先以SiO2的形式存在,然后与MgO反应生成Mg2SiO4。质量分数x为0.5%的SiO2掺杂提高了BSTM陶瓷的致密度及可调率,并降低了其微波损耗,此时,陶瓷样品的可调率为16.21%,Q.f=109.5 GHz。随着SiO2掺杂量的进一步增加,BSTM陶瓷的可调率有所提高,介电常数逐渐降低,微波品质因数先降后升。在x=3.0%时,BSTM陶瓷的可调率达17.6%,Q.f=89 GHz。更多还原

【Abstract】 0.4Ba0.6Sr0.4TiO3-0.6MgO-xSiO2(0≤x≤5.0%)ceramics were prepared by conventional ceramic preparation technique.The effects of SiO2 content on the microstructure and dielectric properties(at low and microwave frequency) of BST-MgO(BSTM) ceramics were investigated.The results of XRD analysis show that SiO2 transforms from SiO2 to Mg2SiO4 in BSTM ceramics with increasing SiO2 content.Doping 0.5%(mass fraction) SiO2 increases the density,improves the tenability and reduces the microwave loss of BSTM ceramics.The tunability and Q?f of BSTM ceramics with 0.5% SiO2 is found to be 16.21% and 109.5 GHz,respectively.With SiO2 content increasing further,the tunability of BSTM ceramics increases,the ?r decreases,while the Q?f decreases first and then increases.When 3%(mass fraction) SiO2 is doped,the tunability of BSTM ceramics reaches 17.6% while its Q·f is 89 GHz.更多还原