【摘要】：自二十世紀(jì)五六十年代以來,過渡金屬氧化物因其獨(dú)特的物理特性,引起越來越多人的關(guān)注,具備層狀鈣鈦礦結(jié)構(gòu)的過渡金屬氧化物更是因其多樣的奇異物理特性備受追捧,并且,通過摻雜的方式改變其物性從而更好地滿足工業(yè)生產(chǎn)需求已成為國內(nèi)外課題組的研究熱點(diǎn)。本文主要通過對(duì)高溫超導(dǎo)化合物YBa2Cu3O7-δ(YBCO)和自旋軌道耦合化合物Sr_2IrO_4進(jìn)行制備和摻雜,并研究其結(jié)構(gòu)特性變化,為進(jìn)一步研究其物性變化提供理論參考依據(jù)。采用金屬有機(jī)物沉積法制備YBCO薄膜,更換不同襯底以及對(duì)前驅(qū)液按照不摻雜樣品中Y3+濃度的十分之一進(jìn)行Gd3+和Sm3+摻雜,研究襯底對(duì)薄膜生長的影響以及摻雜對(duì)其結(jié)構(gòu)特性的改變。結(jié)果表明YBCO晶粒無法在與之晶格匹配度低的襯底材料之上進(jìn)行結(jié)晶生長;摻雜后YBCO晶體結(jié)構(gòu)產(chǎn)生了輕微的晶格畸變,且摻雜后膜內(nèi)壓應(yīng)力減弱,導(dǎo)致晶粒c軸取向生長減弱。采用固相反應(yīng)法制備Sr_2IrO_4化合物,通過Sr缺位摻雜的方式引入空位缺陷,利用正電子湮沒技術(shù)通過測試樣品的壽命譜來研究晶體內(nèi)部缺陷隨摻雜濃度的演變行為,結(jié)果表明隨著Sr缺位摻雜濃度的增加,正電子的壽命呈現(xiàn)減小的趨勢,這是因?yàn)楫?dāng)摻雜濃度不斷增強(qiáng)時(shí),樣品內(nèi)部產(chǎn)生輕微的晶格畸變導(dǎo)致空位型缺陷體積變小,從而使缺陷的壽命一直變小;當(dāng)摻雜濃度達(dá)到一定程度時(shí),正電子壽命又呈現(xiàn)變大的趨勢,這是因?yàn)椴糠挚瘴恍腿毕莺蜆悠穬?nèi)某些殘留的氣泡相互作用從而形成了新的復(fù)合型缺陷,導(dǎo)致缺陷體積變大,從而使缺陷的壽命變大,同時(shí)也導(dǎo)致缺陷濃度降低。這種晶格畸變行為在樣品的XRD衍射譜中也有體現(xiàn),具體表現(xiàn)為各主相峰隨著摻雜濃度的增加發(fā)生了輕微的偏移。
[Abstract]:Since the 1950s and 1960s, transition metal oxides have attracted more and more attention because of their unique physical properties, and transition metal oxides with layered perovskite structure have been sought after for their various singular physical properties. In addition, changing its physical properties by doping to better meet the needs of industrial production has become a hot research topic at home and abroad. In this paper, the high temperature superconducting compound YBa2Cu3O7- 未 (YBCO) and the spin orbit coupling compound Sr_2IrO_4 are prepared and doped, and their structural characteristics are studied, which provides a theoretical basis for further study of the physical properties of the superconducting compounds. YBCO thin films were prepared by metal-organic deposition method, different substrates were replaced, and the precursor solution was doped with Gd3 and Sm3 according to the concentration of 1/10 Y3 in the undoped samples. The influence of substrate on the growth of thin film and the change of doping on its structure were studied. The results show that YBCO crystal can not grow on the substrate with low lattice matching, and the doped YBCO crystal structure produces slight lattice distortion, and the compressive stress in the film decreases after doping, which leads to the weakening of c-axis orientation growth of the crystal. Sr_2IrO_4 compounds were prepared by solid state reaction, vacancy defects were introduced by Sr vacancy doping, and the evolution of defects with doping concentration was studied by means of positron annihilation technique. The results show that the lifetime of positron decreases with the increase of Sr vacancy doping concentration. So that the life of defects has been reduced; When the doping concentration reaches a certain level, the positron lifetime increases again, which is due to the interaction between some vacancy defects and some residual bubbles in the sample, resulting in the formation of new composite defects, resulting in the defect volume becoming larger. Thus, the defect life is increased and the defect concentration is reduced. The lattice distortion is also reflected in the XRD diffraction spectrum of the sample, which shows that the main phase peaks deviate slightly with the increase of doping concentration.
【學(xué)位授予單位】：南京郵電大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：O611.62

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 儀寧;索紅莉;劉敏;馬麟;徐燕;李春燕;王田田;;低氟MOD法制備Zr摻雜YBCO厚膜的性能研究[J];人工晶體學(xué)報(bào);2016年09期

2 王醒東;;YBCO超導(dǎo)薄膜的表征與測試方法[J];電工材料;2016年04期

3 程勇;陸益敏;郭延龍;黃國俊;王淑云;朱孟真;黎偉;米朝偉;曹海源;;脈沖激光沉積功能薄膜的研究進(jìn)展[J];激光與光電子學(xué)進(jìn)展;2015年12期

4 田兆蕓;姚建剛;張朝民;尹登峰;江勇;;點(diǎn)缺陷對(duì)L1_2-Al_3Li金屬間化合物熱力學(xué)性能的影響[J];原子與分子物理學(xué)報(bào);2015年04期

5 芮潤生;劉志勇;白傳易;郭艷群;金曉艷;蔡傳兵;;金屬有機(jī)溶液法制備YBa_2Cu_3O_(7-δ)超導(dǎo)薄膜的厚化特性[J];無機(jī)材料學(xué)報(bào);2014年11期

6 賈連鎖;張京德;金橋;;高溫銅氧化物超導(dǎo)體制備技術(shù)的研究進(jìn)展[J];人工晶體學(xué)報(bào);2014年08期

7 徐琬琛;柏躍玲;方建慧;蔡傳兵;;MOD法制備YBCO超導(dǎo)薄膜的研究進(jìn)展[J];材料導(dǎo)報(bào);2013年23期

8 崔利可;王愛琴;李繼文;謝敬佩;;YBCO粉末及薄膜制備方法的研究現(xiàn)狀[J];稀土;2013年05期

9 金建勛;鄭陸海;;高溫超導(dǎo)材料與技術(shù)的發(fā)展及應(yīng)用[J];電子科技大學(xué)學(xué)報(bào);2006年S1期

10 肖立業(yè);超導(dǎo)電力技術(shù)的現(xiàn)狀和發(fā)展趨勢[J];電網(wǎng)技術(shù);2004年09期

相關(guān)碩士學(xué)位論文 前1條

1 谷志剛;退火處理對(duì)LaAlO_3薄膜微結(jié)構(gòu)及性能的影響[D];南京航空航天大學(xué);2008年

，

本文編號(hào)：2303530