Fabrication and Physical Properties of Single-Crystalline Βeta-FeSi Nanowires.

In this study, self-catalyzed β-FeSi nanowires, having been wanted but seldom achieved in a furnace, were synthesized via chemical vapor deposition method where the fabrication of β-FeSi nanowires occurred on Si (100) substrates through the decomposition of the single-source precursor of anhydrous FeCl powders at 750-950 °C. We carefully varied temperatures, duration time, and the flow rates of carrier gases to control and investigate the growth of the nanowires. The morphology of the β-FeSi nanowires was observed with scanning electron microscopy (SEM), while the structure of them was analyzed with X-ray diffraction (XRD) and transmission electron microscopy (TEM). The growth mechanism has been proposed and the physical properties of the iron disilicide nanowires were measured as well. In terms of the magnetization of β-FeSi, nanowires were found to be different from bulk and thin film; additionally, longer β-FeSi nanowires possessed better magnetic properties, showing the room-temperature ferromagnetic behavior. Field emission measurements demonstrate that β-FeSi nanowires can be applied in field emitters.