BST/MgO系铁电移相材料微波电性能的研究

采用正交设计实验方法分析了SnO2、MnCO3、B i2O3和A l2O3添加量对BST/MgO系铁电移相材料微波电性能影响。实验结果表明:SnO2的引入促进样品烧结,有助于降低低频和微波损耗,但过多的加入会产生第二相,会使微波损耗上升。Mn受主取代Ti产生空穴等缺陷,不利于微波损耗的降低,而等价取代类似SnO2的情况,有助于降低微波损耗,但过多的加入会产生第二相,也会使微波损耗上升。B i2O3对材料微波电性能有显著的影响,从离子半径匹配角度,B i2O3一般出现在晶粒间,形成玻璃相,一方面促进烧结,使致密化提高,低频损耗变小;另一方面低熔点的玻璃相引起微波损耗急剧上升。A l2O3对材料电性能影响不显著。

Study on microwave electric properties of phase shifter material based on BST/ MgO

The influence of SnO_2, MnCO_3, Bi_2O_3 and Al_2O_3 contents on the microwave electrical properties of phase shifter material based on BST/ MgO was studied. The results showed that SnO_2 may enhance the sintering of the samples, and reduce low frequency(dielectric) loss and microwave dielectric loss, but the second phase can be formed with excess of SnO_2, leading to the increase in microwave dielectric loss. Mn substitution for Ti, as acceptors, is believed to produce holes, and cause microwave dielectric loss to increase. Similar to SnO_2, the equivalent replacement helps reduce microwave dielectric loss. But with excess of MnCO_3 the second phase is formed, and the microwave dielectric loss is increased. Bi_2O_3 affects remarkably microwave dielectric loss. From ionic radius, Bi_2O_3 is expected to exist at grains boundary and produce glass phase, so it promotes the sintering of samples and reduces low frequency dielectric loss. Additionally, the glass phase with low melting point may also cause microwave dielectric loss to increase remarkably. Al_2O_3 affects little electric property of the material.