Co-doped BisFeTi3O15 thin films （BFCT-x, Bi5Fe1-xCoxTi3O15） were prepared using a sol-gel technique. XRD patterns confirm their single phase Aurivillius structure, and the corresponding powder Rietveld analysis indi...Co-doped BisFeTi3O15 thin films （BFCT-x, Bi5Fe1-xCoxTi3O15） were prepared using a sol-gel technique. XRD patterns confirm their single phase Aurivillius structure, and the corresponding powder Rietveld analysis indicates the change of space group around x ： 0.12. The magnetic hysteresis loops are obtained and ferromagnetism is therefore confirmed in BFCT-x thin films. The remanent magnetization （Mr） first increases and reaches the maximum value of 0.42 emu/cm^3 at x = 0.12 due to the possible Fe^3＋-O Co^3＋ ferromagnetic coupling. When x = 0.25, the Mr increases again because of the dominant Fe^3＋-O Co^3＋ ferromagnetic coupling. The remanent polarization （2Pr） of BFCT-0.25 was measured to be as high as 62 μC/cm2, a 75% increase when compared with the non-doped BFCT-0 films. The 2Pr remains almost unchanged after being subjected to 5.2 × 10^9 read/write cycles. Greatly enhanced ferroelectric properties are considered to be associated with decreased leakage current density.展开更多
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...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。展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No.51072177)the Natural Science Foundation of the Higher Education Institutions of Jiangsu Province,China (Grant No.08KJB140011)
文摘Co-doped BisFeTi3O15 thin films （BFCT-x, Bi5Fe1-xCoxTi3O15） were prepared using a sol-gel technique. XRD patterns confirm their single phase Aurivillius structure, and the corresponding powder Rietveld analysis indicates the change of space group around x ： 0.12. The magnetic hysteresis loops are obtained and ferromagnetism is therefore confirmed in BFCT-x thin films. The remanent magnetization （Mr） first increases and reaches the maximum value of 0.42 emu/cm^3 at x = 0.12 due to the possible Fe^3＋-O Co^3＋ ferromagnetic coupling. When x = 0.25, the Mr increases again because of the dominant Fe^3＋-O Co^3＋ ferromagnetic coupling. The remanent polarization （2Pr） of BFCT-0.25 was measured to be as high as 62 μC/cm2, a 75% increase when compared with the non-doped BFCT-0 films. The 2Pr remains almost unchanged after being subjected to 5.2 × 10^9 read/write cycles. Greatly enhanced ferroelectric properties are considered to be associated with decreased leakage current density.
文摘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。
