New experimental evidence for origin of ferromagnetism ordering in Fe-doped SiC

Fe-doped 6H-SiC polycrystalline powders were synthesized by solid-state reaction of high-purity silicon, graphite and iron powder. X-ray powder diffraction (XRD) and high-resolution transmission electron microscope (HRTEM) analysis showed the presence of little Fe3Si as secondary phase. Temperature-dependent magnetization showed two typical ferromagnetic (FM) transition temperatures located at 438 and 837 K, respectively. These features provided convincing experimental evidence to demonstrate that the presence of Fe3Si is not the nature origin of FM ordering in Fe-doped SiC. It also indicated that trace of Fe-doping in SiC will induce a high-temperature FM arrangement. (C) 2008 Elsevier B.V. All rights reserved.