Facile conversion of Fe nanotube arrays to novel αFe ₂O₃ nanoparticle nanotube arrays and their magnetic properties

A simple template-based calcination treatment method has been developed to convert Fe nanotube arrays to novel α-Fe₂O₃ nanoparticle nanotube arrays (NPNTA). This process can conveniently be extended to fabricate a free-standing, easily oxidized metal oxide nanotube array, which may have future applications in nanoscale optics, electronics, and magnetics. The controlled variability of the diameter and length might be used to tune desired magnetic properties. The anisotropic magnetic property of both the discrepancy of the saturation magnetization (M_s) and coercivity (H_c) is observed for the NPNTA when the magnetic field is applied parallel and perpendicular to the nanoarrays. This remarkable magnetic anisotropy as well as the high H_c value makes these NPNTA can be useful for high-density magnetic recording applications.