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La0.67Sr0.33MnO3基双相复合体系的制备、表征及电磁性能研究
摘要：对于钙钛矿锰氧化物La0.67Sr0.33MnO3的研究，由于这类材料在外场下所展示的巨磁电阻效应，故在读出磁头、磁传感器以及高密度的磁存储器方面具有很好的应用前景，这1领域已成为凝聚态和材料学中的1个重要的研究热点。在这篇论文中，我们将对La0.67Sr0.33MnO3/绝缘体两相复合材料体系进行了如下研究：
首先本文简要地介绍了钙钛矿锰氧化物的晶体结构、电子结构以及锰氧化物中的各种有序态，这是研究锰氧化物巨磁电阻材料的基础,并讨论了影响钙钛矿锰氧化物颗粒度的因素，以及分析了钙钛矿锰氧化物基复合体系研究中存在的问题并提出了本文的研究工作。
其次本文研究了钙钛矿锰氧化物La0.67Sr0.33MnO3基纳米复合体系La0.67Sr0.33MnO3/SrFe12O19的制备工艺。用溶胶-凝胶法制备了纳米La0.67Sr0.33MnO3多晶粉体和SrFe12O19 ，然后用物理共混法制备了La0.67Sr0.33MnO3/SrFe12O19复合体系材料，并通过XRD，原子力显微分析等对材料进行表征。
最后本文研究了在钙钛矿锰氧化物铁磁性导体中掺入绝缘相对体系后对其电性、磁性以及磁电阻效应产生的影响，并研究了磁性绝缘体SrFe12O19复合后La0.67Sr0.33MnO3/ SrFe12O19的磁性、电性以及磁电阻效应，并对本文的研究工作作出总结。
关键词：La0.67Sr0.33MnO3/SrFe12O19；复合体系；电磁性能
The study of synthesis ,characterization and magnetic and electric properties of La0.67Sr0.33MnO3 composites
ABSTRACT：The study of La0.67Sr0.33MnO3 perovskite manganites that exhibit colossal magnetoresistance effect has been an important object of condensed matter physics and material science due to the potential applications of colossal magnetoresistance materials in read heads for had disks, sensors and magnetic memories. In this thesis, we devoted our effort to the study of the La0.67Sr0.33MnO3/insulator composites as follows:
At first, this article gives a reference to perovskite manganites for its crystalloid structures, electronically structures and variety configuration, and it’s the rudiment for researching parasite manganites. It talks over the factors which win on the granulometric of perovskite manganites , and it analyzing that questions which lie on the study of rudimental institutions and compound institutions of perovskite manganites and weigh in with researching yakka of this article .
In the next place ,it looks into the facture technics of La0.67Sr0.33MnO3 perovskite manganites and La0.67Sr0.33MnO3/SrFe12O19 . nm polycrystal La0.67Sr0.33MnO3 and SrFe12O19 is made with collosol and gelatum ways , then La0.67Sr0.33MnO3/SrFe12O19 is made by use of physical mixing and make token for materials by XRD and AFM .
At last ,the influence of the magnetic and electric properties and magnetoresistance of the nanocomposites is investigated after swing in with insulator composites ,and it sees into the magnetic and electric properties and magnetoresistance of the nanocomposites La0.67Sr0.33MnO3/SrFe12O19 ,and make summing-up for the researches of this article .
Keywords：La0.67Sr0.33MnO3/SrFe12O19 ; composites system；magnetic and electric properties
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