引用本文:
【打印本页】   【HTML】   【下载PDF全文】   View/Add Comment  【EndNote】   【RefMan】   【BibTex】
←前一篇|后一篇→ 过刊浏览    高级检索
本文已被:浏览 1161次   下载 1119 本文二维码信息
码上扫一扫!
分享到: 微信 更多
Preparation and Superparamagnetism of Nano-Ni/mesoporous SiO2 Composites
Fan Sanqiang,Cai Weili,Mou Jimei,Chen Huiyu
Author NameAffiliationE-mail
Fan Sanqiang Department of Materials Science and Engineering, University of Science and Technology of China, Hefei 230026  
Cai Weili Department of Materials Science and Engineering, University of Science and Technology of China, Hefei 230026 wlcai@ustc.edu.cn  
Mou Jimei Department of Materials Science and Engineering, University of Science and Technology of China, Hefei 230026  
Chen Huiyu Department of Physics, University of Science and Technology of China, Hefei 230026  
Abstract:
Nano-Ni/mesoporous SiO2 composites were obtained by reducing Ni2+-doped SiO2 xerogels in H2, which were prepared via a sol-gel route. The average size of nano-Ni particles in mesoporous composites was estimated at 11~12nm from TEM (Transmission Electron Microscope) photographs. The results of magnetic measurements show that compared with the conventional nano-Ni particles, the Ni particles in nano-Ni/mesoporous SiO2 composites remain superparamagnetic state when their particle size is larger than the critical size of Ni calculated theoretically. Elevation of the reduction temperature promotes transformation of nano-Ni particles in mesoporous composites into the superparamagnetic state within a certain range of temperature.
Key words:  Superparamagnetism, Mesoporous composites, Magnetic anisotropy
FundProject:国家自然科学基金资助项目(19974041)
纳米Ni/SiO2介孔复合体的制备与超顺磁性
樊三强,蔡维理*,牟季美,陈慧余
摘要:
采用溶胶—凝胶法制备了含Ni2+的SiO2干凝胶,再通过化学还原得到了纳米Ni/SiO2介孔复合体。从样品的透射电子显微镜观测结果可估算出,介孔复合体中Ni粒子的尺寸约为11~12nm。样品的磁性测量结果表明,与通常的Ni纳米颗粒相比,纳米Ni/SiO2介孔复合体中纳米Ni粒子的粒径在大于理论计算的纳米Ni粒子的临界尺寸时,仍能够保持超顺磁状态。在一定温度范围内,提高还原温度有利于复合体中纳米Ni粒子向超顺磁状态转变。
关键词:  超顺磁性  介孔复合体  磁各向异性
DOI:10.1088/1674-0068/14/2/205-210
分类号: