Superparamagnetic FeCo and FeNi Nanocomposites Dispersed in Submicrometer-Sized C Spheres
详细信息 查看全文
- 作者：E. M. M. Ibrahim ; Silke Hampel ; A. U. B. Wolter ; M. Kath ; A. A. El-Gendy ; R. Klingeler ; Christine T盲schner ; Vyacheslav O. Khavrus ; Thomas Gemming ; Albrecht Leonhardt ; Bernd B眉chner
- 刊名：The Journal of Physical Chemistry C
- 出版年：2012
- 出版时间：October 25, 2012
- 年：2012
- 卷：116
- 期：42
- 页码：22509-22517
- 全文大小：544K
- 年卷期：v.116,no.42(October 25, 2012)
- ISSN：1932-7455
文摘
Magnetic spheres with average diameter 100 nm, consisting of FeCo and FeNi nanomagnets (with average diameters 5.9 卤 1 and 4.6 卤 0.3 nm, respectively) dispersed in spherical carbon colloid have been synthesized using the radio frequency plasma-enhanced chemical vapor deposition technique. The nanoparticles are tightly embedded in the C matrix and well protected from oxidation. Superparamagnetic features such as typical Langevin-like magnetization curves are observed for the nanocomposites. A comprehensive analysis of the presence of dipolar interactions has been carried out within the framework of the mean-field model. The size of the nanoparticles constituting the carbon-spheres is near to the optimal value where N茅el losses are maximal and considerable Neel-type specific absorption rates are observed. The material may hence provide a new material-based approach to realize biocompatibly protected superparamagnetic beads for application in biological environments, in particular, for magnetic hyperthermia.