Four kinds of Fe-Cr ultrafine particle (UFP) samples were synthesized by a hydrogen plasma-metal reaction method. The UFP samples were examined by X-ray diffraction, electron transmission microscopy and chemical analysis and specific surface area analysis. The oxidation and magnetic properties of as prepared UFP samples were investigated. The crystal structure of Fe-Cr UFP samples is the same as that of the master bulk samples, but the Cr content in Fe-Cr UFP samples is richer than that in bulk samples. The characteristics of Fe-Cr UFP samples such as particle shape, mean particle size and specific surface area show strong dependence on the Cr content. Oxidation for the Fe-Cr UFP occurs easily at a temperature even lower than 473 K and the oxided Fe-Cr UFP samples change from a acicular shape into angular shape with increasing Cr content. Although the saturation magnetization of the UFP samples is smaller than that of the corresponding bulk samples, the difference in saturation magnetization between the two kinds of samples becomes small as the Cr content increases.
- Crystalline structure
- Ultrafine particle
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics