發(fā)布時(shí)間：2018-02-20 03:58

  本文關(guān)鍵詞： BiFeO_3陶瓷 納米管 摻雜 電導(dǎo)率 磁性　出處：《天津師范大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：越來(lái)越多的人們開始注意多鐵材料,因?yàn)樗麄兊奈锢硖匦院蜐撛诘奶匦赃m合應(yīng)用于多功能設(shè)備上。鐵酸鉍是一種多鐵材料,它具有高的居里溫度(TC～1103K)和高的聶耳溫度(TN～43K),在室溫下鐵酸鉍同時(shí)具有鐵電和磁性的特性,使其具有很好的應(yīng)用前景。但鐵酸鉍還有其自身的缺點(diǎn),其中包括雜項(xiàng)較多,弱的鐵磁性,低的磁電耦合系數(shù)和弱的反鐵磁特性。為了克服這些問(wèn)題,本論文采用元素?fù)诫s和制備低維納米線材料嘗試改善之。 首先我們使用固相法制備出La0.1Bi0.9AgxFe(1-x)03(LBFAx, x=0-0.05)陶瓷。Ag的摻雜使樣品的密度提高并且顆粒尺寸細(xì)化。與此同時(shí)發(fā)現(xiàn),Ag的摻雜能夠大大提高樣品的電導(dǎo)率,漏電流提升了2-4個(gè)數(shù)量級(jí)。我們將摻雜引起的電導(dǎo)率提升歸因于樣品中的氧空位濃度的提高。 其次,La0.1Bi0.9-xSrxFeO (3-x/2)(LBFSx0≤x≤0.8)陶瓷同樣使用固相反應(yīng)法制備而成。我們討論了其磁學(xué)和電學(xué)特性。隨著Sr的摻入晶體結(jié)構(gòu)從扭曲的鈣鈦礦結(jié)構(gòu)向偽立方結(jié)構(gòu)轉(zhuǎn)變。電學(xué)和磁學(xué)性質(zhì)的改變與Sr的摻入有很大關(guān)系。30%-Sr的樣品呈現(xiàn)了最低的漏電流、介電常數(shù)和介電損耗的值。60%-Sr的樣品的飽和磁化強(qiáng)度最大,其值為4.5emu/g。 最后,使用基于溶膠-凝膠的靜電紡絲法成功制成出鐵酸鉍一維納米結(jié)構(gòu)。我們可以清晰的看到4000℃和450℃的一維納米管狀結(jié)構(gòu)。內(nèi)經(jīng)為55nm,壁的厚度為20nm。并且納米管具有大的比表面積,能夠提升鐵酸鉍的磁學(xué)特性。同時(shí)觀察到納米管的飽和磁化強(qiáng)度增高,滯后損失減少。為改善鐵酸鉍的磁性找到了一條新的途徑,使其在電磁設(shè)備里有更大的應(yīng)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，

本文編號(hào)：1518708