Experimental observation and theoretical calculation of magnetic properties in Fe-doped cubic SiC nanowires

Fe-doped SiC nanowires samples were fabricated using high-purity carbon nanotubes, SiO and Fe powders as starting materials. The surface morphology, microstructure and chemical composition of the samples were investigated by field emission scanning electron microscopy, high resolution transmission electron microscopy and X-ray photoelectron spectroscopy, respectively. The results reveal that the samples crystallize with cubic structure and grow along the [1 1 1] direction. Results of magnetic measurement show the samples exhibit room temperature ferromagnetism without the formation of magnetic clusters. The saturation magnetization of the samples decreases with the increase of Fe concentration. From the first-principles calculations, it is strongly proposed that the magnetic state are depend on the distance between Fe dopant atoms. Combined the theoretical calculations with the experimental results, it is suggested that C vacancies play a vital role in determining the magnetic properties in Fe-doped SiC nanowires.