添加锂微量掺杂物对锰掺杂ZnO铁磁性能的提高  

Enhancement of Ferromagnetic Property of Mn Doped ZnO by Adding Microcontent of Li Dopant

作　　者：王古平[1] 李志刚[1] 陈卫平[1] 

机构地区：[1]台州学院物理与电子工程学院,浙江台州318000

出　　处：《稀有金属》2011年第4期520-524,共5页Chinese Journal of Rare Metals

基　　金：国家自然科学基金青年基金(51001078)资助项目;台州学院校立项目(09ND11)资助

摘　　要：利用溶胶-凝胶法制备了Mn掺杂和Mn,Li共掺ZnO室温铁磁性半导体,分别采用X射线衍射(XRD),X光电子能谱(XPS),紫外-可见分光光度计(UV-VIS)和振动样品磁强计(VSM)研究了添加Li微量掺杂物对Mn掺杂ZnO的晶体结构、电子价态、能带宽度和铁磁特性的影响。结果表明:添加Li微量掺杂物明显提高了Mn掺杂ZnO的铁磁特性,使Mn掺杂ZnO的饱和磁化强度提高了31.52%;Li+存在于Mn掺杂ZnO晶体结构的间隙位置,晶胞参数a和c略有增加,晶粒尺寸减小;Mn离子均以+2价存在,没有Li和Mn氧化物杂质相的存在;同时,添加Li微量掺杂物使Mn掺杂ZnO的能带宽度减小了0.144 eV,载流子发生变化。铁磁性的提高归因于Li的引入导致ZnO晶格中的间隙电子掺杂和间隙缺陷的产生及载流子的变化,以及Mn2+-Mn2+间接铁磁性交换耦合的增强。Mn doped and Mn,Li codoped ZnO were synthesized by sol-gel method.Influences of microcontent additional Li dopant on magnetic property,crystal structure,and electronic valence state and energy gap of Mn-doped ZnO were investigated with XRD,XPS,UV-VIS and VSM,respectively.These results showed that additional Li microcontent dopant enhanced the ferromagnetic property of Mn-doped ZnO obviously.The saturation magnetization of Mn-doped ZnO was increased by 31.52% after adding Li microcontent dopant.With adding Li microcontent dopant,the lattice constant a and c increased owing to that Li＋ existed in interstitial site of Mn-doped ZnO crystal structure,and the grain size decreased.Mn ions of Mn-doped ZnO with and without Li dopant were both ＋2.There were no Li and Mn oxide compound impurities in the Mn-doped ZnO with and without Li dopant.At the same time,the band gap of Mn-doped ZnO reduced 0.144 eV after doping microcontent additional Li.Ferromagnetism enhancement attributed to interstitial electron doping and defects with ZnO crystal lattice induced by additional Li-doping.

关 键 词：ZNO 添加Li掺杂物 间隙电子掺杂 间隙缺陷 铁磁性能 

分 类 号：TN304.7[电子电信—物理电子学]