Arya Ved Prakash, Prasad V, Kumar P S Anil
Department of Physics, Indian Institute of Science, Bangalore 560012, India.
J Nanosci Nanotechnol. 2009 Sep;9(9):5406-10. doi: 10.1166/jnn.2009.1165.
Iron nanoparticles are embedded in multiwall carbon nanotubes by the chemical vapor deposition, where benzene and ferrocene are taken as precursor materials. Varying quantity of iron particles are embedded in these tubes by taking different amount of ferrocene. These particles exhibit a magnetic moment up to 98 emu/g and an enhanced coercivity in the range of 500-2000 Oe. Negative magnetoresistance approximately 10% is observed in the presence of magnetic field up to 11 T applied at various temperatures in the range of 1.3 K-300 K. It is argued that the enhanced coercivity is due to the shape anisotropy. The negative magnetoresistance is believed to be due to the weak localization and spin dependent scattering of electrons by the ferromagnetic particles. In addition we also observe a dependence of the magnetoresistance on the direction of applied field and this is correlated with the shape anisotropy of the Fe particles.
通过化学气相沉积法将铁纳米颗粒嵌入多壁碳纳米管中，其中以苯和二茂铁作为前驱体材料。通过使用不同量的二茂铁，可在这些碳纳米管中嵌入不同数量的铁颗粒。这些颗粒表现出高达98 emu/g的磁矩以及在500 - 2000奥斯特范围内增强的矫顽力。在1.3 K至300 K的不同温度下施加高达11特斯拉的磁场时，观察到约10%的负磁阻。有人认为增强的矫顽力是由于形状各向异性。负磁阻被认为是由于铁磁颗粒对电子的弱局域化和自旋相关散射。此外，我们还观察到磁阻对施加磁场方向的依赖性，这与铁颗粒的形状各向异性相关。
