Magnetic nanotubes produced by hydrogen reduction

FePt and Fe₃O₄ nanotubes are produced by hydrogen reduction in nanochannels of porous alumina templates and investigated by electron microscopy, x-ray diffraction, and superconducting quantum interference device magnetometry. Loading the templates with an Fe chloride and Pt chloride mixture, followed by hydrogen reduction at 560 °C, leads to the formation of ferromagnetic FePt nanotubes in the alumina pores. An Fe nitrate solution, thermally decomposed at 250 °C and reduced in hydrogen for 2.5 h at the same temperature, yields Fe₃O₄ tubes. The versatility of the method indicates that materials with a wide range of parameters can be produced. © 2004 American Institute of Physics.