铁酸铋陶瓷和纳米线的制备及异价元素掺杂对其物性的影响研究

发布时间：2018-02-20 03:58

  本文关键词： BiFeO_3陶瓷 纳米管 掺杂 电导率 磁性　出处：《天津师范大学》2015年硕士论文　论文类型：学位论文

【摘要】：越来越多的人们开始注意多铁材料,因为他们的物理特性和潜在的特性适合应用于多功能设备上。铁酸铋是一种多铁材料,它具有高的居里温度(TC～1103K)和高的聂耳温度(TN～43K),在室温下铁酸铋同时具有铁电和磁性的特性,使其具有很好的应用前景。但铁酸铋还有其自身的缺点,其中包括杂项较多,弱的铁磁性,低的磁电耦合系数和弱的反铁磁特性。为了克服这些问题,本论文采用元素掺杂和制备低维纳米线材料尝试改善之。 首先我们使用固相法制备出La0.1Bi0.9AgxFe(1-x)03(LBFAx, x=0-0.05)陶瓷。Ag的掺杂使样品的密度提高并且颗粒尺寸细化。与此同时发现,Ag的掺杂能够大大提高样品的电导率,漏电流提升了2-4个数量级。我们将掺杂引起的电导率提升归因于样品中的氧空位浓度的提高。 其次,La0.1Bi0.9-xSrxFeO (3-x/2)(LBFSx0≤x≤0.8)陶瓷同样使用固相反应法制备而成。我们讨论了其磁学和电学特性。随着Sr的掺入晶体结构从扭曲的钙钛矿结构向伪立方结构转变。电学和磁学性质的改变与Sr的掺入有很大关系。30%-Sr的样品呈现了最低的漏电流、介电常数和介电损耗的值。60%-Sr的样品的饱和磁化强度最大,其值为4.5emu/g。 最后,使用基于溶胶-凝胶的静电纺丝法成功制成出铁酸铋一维纳米结构。我们可以清晰的看到4000℃和450℃的一维纳米管状结构。内经为55nm,壁的厚度为20nm。并且纳米管具有大的比表面积,能够提升铁酸铋的磁学特性。同时观察到纳米管的饱和磁化强度增高,滞后损失减少。为改善铁酸铋的磁性找到了一条新的途径,使其在电磁设备里有更大的应用前景。
[Abstract]:More and more people are beginning to pay attention to multiferric materials because their physical and potential properties are suitable for use in multifunctional equipment. Bismuth ferrate is a kind of polyferric material. It has both ferroelectric and magnetic properties at room temperature, which makes it have good application prospects. However, bismuth ferrate has its own disadvantages, including a lot of miscellaneous. In order to overcome these problems, the low ferromagnetism, the low magnetoelectric coupling coefficient and the weak antiferromagnetic properties have been studied in this paper. In order to overcome these problems, element doping and preparation of low virium nanowire materials are used to improve them. First of all, we prepared La0.1Bi0.9AgxFeO1-xN03LBFAx, xn0. 05) ceramics by solid state method. The doping of La 0. 1 Bi 0. 9 Agx Fe 1-x 0. 05) ceramics can increase the density of the samples and refine the particle size. At the same time, it is found that the doping of Ag can greatly improve the conductivity of the samples. The leakage current is increased by 2-4 orders of magnitude. We attribute the increase of conductivity caused by doping to the increase of oxygen vacancy concentration in the sample. Secondly, La0.1Bi0.9-xSrxFeO 3-x / 2o (LBFSx0 鈮，

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