Co离子注入TiO2薄膜的显微结构和磁性研究  

Microstructure and magnetic properties of the cobalt ions implanted TiO_2 films

作　　者：丁芃[1] 刘发民[1] 杨新安[2] 李建奇[2] 

机构地区：[1]北京航空航天大学物理科学与核能工程学院,微纳测控与低维物理教育部重点实验室,北京100191 [2]北京凝聚态物理国家实验室,中国科学院物理研究所,北京100190

出　　处：《物理学报》2011年第3期515-522,共8页Acta Physica Sinica

基　　金：北京航空航天大学博士研究生创新基金(批准号:292122)资助的课题~~

摘　　要：利用直流磁控溅射技术在玻璃衬底上沉积了TiO2薄膜,并对其进行了Co离子注入,最后在真空中500℃退火50min,得到系列薄膜样品.利用剥离-分散方法制备了薄膜的透射电镜样品,并用扫描电镜(SEM)、X射线能量散射谱(EDX)和高分辨透射电镜(HRTEM)对样品做了近似原位观察,研究了薄膜样品中不同Co离子注入深度的成分分布和显微结构.结果表明,薄膜呈锐钛矿结构,Co元素主要分布在薄膜表层,Co离子的注入使TiO2薄膜的晶粒被部分破坏,并形成CoO,而500℃退火处理可以修复被破坏的晶粒,促进薄膜更好地结晶并且使CoO融和到TiO2晶格中.振动样品磁强计(VSM)测试结果表明,Co离子注入TiO2薄膜在室温下表现铁磁性,真空中的退火处理可以使其铁磁性增强,铁磁性可以用结合磁极子(bound magnetic polaron,BMP)理论来解释.TiO2 thin films were prepared by direct current magnetron sputtering on glass substrates,then were implanted by cobalt ions,and finally annealed at 500 ℃ for 50 min. Specimens for transmission electron microscopy were prepared by peeling-scattering technology,and were observed in situ by scanning electron microscopy （SEM）,energy dispersive X-ray （EDX） and high resolution transmission electron microscopy （HRTEM）. The films were identified as anatase structure. The Co ions exist mainly in a thin layer beneath the surface of the films. The implanted Co ions damage the TiO2 crystals and some of them exist as CoO. The annealing treatment could repair the TiO2 grains and make the Co ions diffuse into the TiO2 lattice. The vibrating sample magnetometer （ VSM） measurements show that the Co ion implanted TiO2 films are ferromagnetic at room temperature and the annealing treatment in vacuum could enhance the ferromagnetism,which could be explained within the scope of the BMP theory.

关 键 词：Co注入TiO2薄膜 电镜原位观察 室温铁磁性 

分 类 号：O484.43[理学—固体物理]