Fe-filled carbon nanotube array with high coercivity

Fe-filled carbon nanotube (CNT) array was fabricated using an excessive-catalyst injection chemical deposition method. SEM and TEM characterizations showed that the well-aligned CNTs were ∼80 μm in length, with outer diameter of 20–50 nm and inner diameter of 10–20 nm. The inner cavity of the CNT was filled with Fe nanowires quasi-continuously, which can be used for reference in synthesis of in situ one-dimensional nanocomposite. Magnetic properties measurements revealed that the array exhibited high coercivity of 732 Oe, higher than that of bulk iron (0.9 Oe) and Fe-filled CNTs of most previous references. And the effect of the macroscopic length of the CNTs on the magnetic properties of the array is preliminarily studied. The high coercivity and the structure of single-domain Fe nanowires isolated by antiferromagnetic CNTs make it a promising candidate for high-density magnetic recording media.