The role of γ-iron nanoparticulates in the growth of carbon nanotubes

被引:10
作者
Khasanov, Airat [1 ]
He, Jian [2 ]
Gaillard, Jay [3 ]
Yang, Keqin [3 ]
Rao, Apparao M. [3 ]
Cameron, C. Michelle [4 ]
Schmeltzer, J. M. [4 ]
Stevens, John G. [4 ]
Nath, Amar [4 ]
机构
[1] Univ N Carolina, Mossbauer Effect Data Ctr, Asheville, NC 28804 USA
[2] Clemson Univ, Complex & Adv Mat Lab, Clemson, SC 29634 USA
[3] Clemson Univ, Dept Phys & Astron, Clemson, SC 29634 USA
[4] Univ N Carolina, Dept Chem, Asheville, NC 28804 USA
基金
美国国家科学基金会;
关键词
D O I
10.1063/1.2937125
中图分类号
O59 [应用物理学];
学科分类号
摘要
Carbon nanotubes (similar to 200 nm diameter) are grown by chemical vapor deposition using catalytic iron particles. Mossbauer spectroscopy enables differentiation among relatively large Fe3C, alpha-Fe, and nanosized superparamagnetic fee gamma-Fe particles. The antiferromagnetic configuration of gamma-Fe nanoparticles yields a significant fraction of uncompensated spins, producing a weak ferromagnetism that allows estimation of size (2-3 nm) via magnetization in zero field versus variable field cooling. This property of gamma-Fe nanoparticles has not been previously employed. We propose that the surfaces of 200 nm iron carbide particles are covered with nanosized gamma-Fe and graphitized carbon that participate in the catalytic growth of nanotubes. (C) 2008 American Institute of Physics.
引用
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页数:3
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