Abstract
Figure Persented: High-aspect-ratio Fe 1-x Mn x Si nanowires with room-temperature ferromagnetism were synthesized by a chemical vapor deposition (CVD) method in one step. This is the first report of ternary silicide nanowires using magnetic Mn ions to partially replace metal sites in the host matrix. Here we report the excellent magnetic characteristics of Fe 1-x Mn x Si nanowires, which exhibit strong ferromagnetism at room temperature and high magnetoresistance (MR) variation. As-synthesized Fe 1-x Mn x Si nanowires show a hyperbranched morphology and a spin-disorder behavior. The strong spin interaction in Fe 1-x Mn x Si nanowires, induced by the substitution of Fe sublattices for magnetic Mn ions, was revealed in the hysteresis loops. The magnetization versus magnetic field (M-H) curves of Fe 1-x Mn x Si nanowires are much less sensitive to the temperature variation from 10 to 300 K than those of FeSi nanowires. Remarkably, the excellent MR performance, -41.6% at 25 K with a magnetic field of 9 T, was demonstrated in an individual Fe 0.88 Mn 0.12 Si nanowire. © 2012 American Chemical Society.