Co^+离子注入单晶TiO_2铁磁性来源与微结构研究  

The Structural,Ferromagnetic Properties of Single-crystal TiO_2 Implanted with Co Ions

作　　者：钟火平[1] 李公平[1,2] 许楠楠[1] 李天晶[1] 龚恒风[1] 陈景升[3] 

机构地区：[1]兰州大学核科学与技术学院,甘肃兰州730000 [2]山东大学晶体材料国家重点实验室,山东济南250100 [3]新加坡国立大学材料科学工程系,新加坡117608

出　　处：《原子核物理评论》2012年第4期414-418,共5页Nuclear Physics Review

基　　金：兰州大学磁学与磁性材料教育部重点实验室开放课题(LZUMMM2010012);山东大学晶体材料国家重点实验室开放课题(KF0901)~~

摘　　要：在室温下,将能量为80keV,注量分别为1×1016和1×1017ions/cm2的Co+离子注入到10mm×10mm×0.5mm的单晶TiO2样品。在氮气保护下,Co+离子注量为1×1017ions/cm2时样品在温度为900℃的条件下退火30min。利用超导量子干涉仪(SQUID)测量样品磁性,并应用X射线衍射(XRD)和扩展边X射线吸收精细结构谱(EXAFS)研究Co+离子注入后样品的微观结构。样品磁性测量结果表明:Co+离子注入后的样品具有室温铁磁性,并且其饱和磁化强度的大小与Co+离子注量及样品是否经退火处理有关。EXAFS研究表明:Co元素在Co+离子注量为1×1017ions/cm2的样品中主要以团簇形式存在;样品经退火处理后,Co团簇消失,并发现Co部分替代TiO2单晶中的Ti。Co+离子注入后,在样品中形成Co团簇与否受离子注量的影响。阐述了样品微观结构与铁磁性来源之间的关系。At room temperature,monocrystalline plates of rutile(TiO 2) were implanted with cobalt ions of an energy of 80keV to fluences of 1×10 16 and 1×10 17 ions / cm 2 respectively.The 1×10 17 ions / cm 2 Coimplanted samples were annealed in nitrogen at 900℃for 30min.The magnetic properties of Co-implanted samples were measured with a superconducting quantum interference device magnetometer(SQUID) at room temperature.Furthermore,the X-ray diffraction(XRD) and Extended X-ray Absorption Fine Structure(EXAFS) were applied to investigate the structural and compositional properties of Co-implanted samples.The magnetic measurements of samples showed that the size of the saturation magnetization of the Co-implanted samples were related to the fluence of ions,and the saturation magnetization of the sample after annealed decreased significantly.The EXAFS measurements showed the presence of cobalt metallic clusters in the sample implanted to ion fluence of 1×10 17 ions / cm 2.The Co metallic clusters disappeared in the sample after annealed,and resulted in the oxidized Co,which is presumed to substitute into the Ti site.The formation of Co clusters or not was determined by the ion fluence.The relation between ferromagnetic behavior and microscopic structure of the Co-implanted samples is discussed.

关 键 词：稀磁半导体 单晶TiO2 铁磁性 离子注入 EXAFS 

分 类 号：O434.19[机械工程—光学工程] O472.5[理学—光学]