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 degreesC, leads to the formation of ferromagnetic FePt nanotubes in the alumina pores. An Fe nitrate solution, thermally decomposed at 250 degreesC 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. (C) 2004 American Institute of Physics.