摘要
采用溶胶-凝胶工艺制备了磁性Co掺杂TiO2基稀磁半导体的纳米颗粒,在空气氛围中以不同温度对样品进行退火处理.通过差热/热重综合热分析仪(TG-DTA)、X射线衍射仪(XRD)、拉曼光谱(Raman)、透射电镜(TEM)分析了纳米颗粒的结构和相变温度.使用振动样品磁场计(VSM)测试样品磁性能.研究发现:退火温度较低时样品为锐钛矿结构,在823K时出现少量金红石相,当退火温度为873K时,样品基本转变成金红石结构,同时析出少量CoTiO3.退火温度同时对样品的磁性有较大影响.随着退火温度的升高,样品室温下的M-H曲线由顺磁形式向铁磁形式转变.退火温度为873K时,我们得到了具有室温铁磁性的Ti0.975Co0.025O2纳米颗粒.
Co-doped TiO2 diluted magnetic semiconductor nanoparticles were prepared by sol-gel method,and were annealed in air under different temperatures.The crystal structure and the phase transition temperature of the nanoparticles were analyzed by thermogravimetry-differential thermal analysis（TG-DTA）,X-ray diffraction（XRD） patterns,Raman spectroscopy and transmission electron microscope（TEM）.The magnetic properties of the nanoparticles were measured by vibrating sample magnetometer（VSM）.It is found that anatase structure exists under lower annealing temperature.A small quantity of rutile phase appears when the temperature was up to 823 K,and rutile has become the dominant component when the annealing temperature reaches to 873 K with a little amount of CoTiO3.The magnetic properties of the samples are also seriously influenced by the annealing temperature.A transition from paramagnetism to ferromagnetism is observed in room temperature M-H curves with the increase of annealing temperature.Room temperature ferromagnetic Ti0.975Co0.025O2 nanoparticles were successfully obtained after annealed at 873 K.
出处
《吉林师范大学学报（自然科学版）》
2010年第2期78-81,共4页
Journal of Jilin Normal University:Natural Science Edition
基金
吉林省科技发展计划项目(20082112)
四平市科技发展计划项目(2008018)
