Free-Standing and Single-Crystalline Fe sub(1-x)Mn sub(x)Si Nanowires with Room-Temperature Ferromagnetism and Excellent Magnetic Response

• Published in: ACS nano Vol. 6; no. 6; pp. 4884 - 4891-4884-4891
• Main Authors: Hung, Min-Hsiu, Wang, Chiu-Yen, Tang, Jianshi, Lin, Ching-Chun, Hou, Te-Chien, Jiang, Xiaowei, Wang, Kang L, Chen, Lih-Juann
• Format: Journal Article
• Language: English
• Published: 06.06.2012
• Subjects: Chemical vapor deposition; Ferromagnetism; Hysteresis loops; Iron; Magnetic fields; Magnetization; Magnetoresistivity; Manganese; Nanowires
• ISSN: 1936-0851; 1936-086X
• DOI: 10.1021/nn300344k

High-aspect-ratio Fe sub(1-x)Mn sub(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 sub(1-x)Mn sub(x)Si nanowires, which exhibit strong ferromagnetism at room temperature and high magnetoresistance (MR) variation. As-synthesized Fe sub(1-x)Mn sub(x)Si nanowires show a hyperbranched morphology and a spin-disorder behavior. The strong spin interaction in Fe sub(1-x)Mn sub(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 sub(1-x)Mn sub(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 sub(0.88)Mn sub(0.12)Si nanowire.