【摘要】 用传统固相烧结法制备了Bi5–xEuxFe0.5Co0.5Ti3O15(BEFCT–x:x=0,0.35,0.55,0.85)陶瓷样品,对比研究了它们的结构和电磁性能。X射线衍射分析表明:掺杂未导致明显杂相,材料的剩余极化(2Pr)随掺杂量的增加呈先增加后减小的变化趋势,在Eu掺杂量为0.55时,材料的2Pr达到最大值,为11.2μC/cm2,升幅达143%,可以由Eu掺杂导致氧空位的抑制和铋氧层的破坏所形成的竞争机制解释。随Eu含量的增加,材料的剩余磁化单调上升,最大达到0.28 A m2/kg,比未掺杂时增加了2个数量级,从晶格失配、耦合增强以及共生结构等方面的综合效果解释了这一现象。材料的介电温度谱显示,Eu掺杂未明显损害材料的热稳定性,Eu掺杂所导致的介电损耗行为可能与氧空位或其他点缺陷有关联。更多还原

【Abstract】 The polycrystalline Bi5–xEuxFe0.5Co0.5Ti3O15(BEFCT–x: x = 0,0.35,0.55,0.85) ceramics were prepared by a solid state reaction method.Their structure-property relations were investigated.The crystal structure of the samples was determined by X-ray diffraction(XRD).There were no secondary phases identified by XRD.The remanent polarization(2Pr) firstly increased and then decreased with the increase of Eu content(x).The remanent polarization reached a maximum vaule of 11.2 μC/cm2 when x = 0.55.The competition mechanism between the decrease of oxygen vacancies and the deterioration of bismuth oxide layers was analyzed.The remanent magnetization increased to a maximum value of 0.28 A?m2/kg with increasing the Eu content,due to the joint effects of lattice mismatch,enhanced ferromagnetic coupling and intergrowth contribution.The measurements of dielectric permittivity showed that the thermal stability of the samples was not damaged.The effect of Eu doping is associated with oxygen vacancies or other point defects.更多还原