形貌对Co掺杂ZnS纳米结构室温铁磁性的影响  

Effects of morphology on the room-temperature ferromagnetism of Co:ZnS nanostructures

作　　者：杨娜[1] 刘晓芳[1] 于荣海[1] 

机构地区：[1]北京航空航天大学材料科学与工程学院,北京100191

出　　处：《中国科技论文》2013年第3期247-250,共4页China Sciencepaper

基　　金：高等学校博士学科点专项科研基金资助项目(20090002110007;20111102120002);国家自然科学基金资助项目(51102006)

摘　　要：采用溶剂热法通过改变溶剂种类,合成了具有不同形貌的Co:ZnS纳米结构。采用X射线衍射、透射电子显微镜、X射线光电子能谱和超导量子干涉仪对样品的形貌、结构、元素价态及磁学性能进行了研究,以揭示Co:ZnS纳米结构室温铁磁性的物理机制。结果表明:去离子水中制备的Co:ZnS为纳米颗粒的团聚体,包含立方ZnS和六方ZnS双相,而在乙二胺和水混合溶剂中制备的样品为六方ZnS相并呈纳米棒形貌;掺杂Co元素在样品中为2+价态,替代了ZnS晶格中Zn2+离子的位置;不同形貌的Co:ZnS均具有明显的室温铁磁性,然而纳米颗粒的饱和磁矩值明显高于纳米棒,Co:ZnS铁磁性随形貌的变化可归因为结构缺陷对磁性能的影响,符合束缚磁极化子理论。Co ： ZnS nanostructures with different morphology have been synthesized via solvothermal method by modifying the type of solvent. In order to explore the ferromagnetic mechanism of the Co：ZnS nanostructures, XRD, TEM, XPS and SQUID tech- niques were used to investigate the morphology, structure, valence state and magnetic property of the samples. The results showed that the Co： ZnS synthesized in deionized water is composed of hexagonal ZnS and cubic ZnS phases, exhibiting an ag- glomeration of nanocrystals; however, the sample prepared in a mixture of deionized water and ethylenediamine showed typical hexagonal ZnS nanorod morphology. XPS measurements demonstrated that the Co ions are in 2＋ valence state and incorporated into ZnS host lattice by replacing Zn^2＋ ion sites. The Co：ZnS nanostructures possess obvious room-temperature ferromagnetism; however, the saturated magnetic moment of the nanocrystals is higher than that of the nanorods. The dependence of ferromagnetism on the morphology of the nanostructures could be attributed to the effects of structural defects on the magnetism which falls in the framework of bound magnetic polaron model.

关 键 词：硫化锌 纳米结构 稀磁半导体 形貌 室温铁磁性 

分 类 号：TB383.1[一般工业技术—材料科学与工程]