【摘要】 讨论了BaO-Ln2O3-TiO2(Ln为镧系稀土元素,下同)、CaO-Li2O-Ln2O2-TiO2、铅基钙钛矿等系列高εr微波介质陶瓷的结构、介电性质,分析了其介电性质随不同A位、B位离子的变化规律。指出A位、B位离子的性质、晶体结构、晶胞大小、材料相组成等对材料的介电系数εr、品质因数Q、谐振频率温度系数τf有决定性影响,钛氧八面体的存在是材料产生高εr的主要原因。随A位离子半径的增大、B位离子半径的减小,材料的εr升高,Q值降低。传统的极化损耗机制不能完全解释该类材料的介电特性。今后的发展趋势是利用复合效应来得到εr更高、Q值更高、同时温度稳定性良好的高性能材料。更多还原

【Abstract】 The structure,microwave behavior of BaO-Ln 2O3-TiO2,CaO-Li2O-Ln2O3-TiO2 and Pb-base perovskite materi als are studied in this paper.The microwave properties of these materi als are investigated in relation to different A and B ions.The dielec tric constant ε r,quality factor Q and the temperature coeffi cient of resonator frequency τ f are mainly determined by the ki nd of A and B ions,crystal structure,unit-cell volume and phase compo sition in materials,TiO6 octahedra plays an very important role in r esulting of high ε r.And ε r increases with the increasing ionic radius of A site and the decreasing ionic radius of B site,me anwhile the Q value decreases.The traditional dielectric polarization theory can not successfully explain the above experimental phenomena.T he developing tendency is to get high-performance microwave dielectric materials with higher ε r by combining different ceramics.更多还原