Facile controlled synthesis and magnetic properties of high-aspect-ratio nickel nanowires prepared by the dropping method

The high aspect ratio nickel nanowires (NWs) with the different sizes and morphologies were synthesized by the improved chemical reduction method, dropping method. By simply adjusting the reaction conditions of the Ni2+ concentration and the precursor solution addition, the average diameter of Ni NWs can be tuned from 85 nm to 350 nm, and the length was about 40 mm. Moreover, the diameter of Ni NWs was more influenced by the Ni2+ concentration than the precursor solution addition and a simple empirical model has been proposed for this dependency. Meanwhile, the morphology change was also systematically investigated. Magnetic measurements showed that the diameter and aspect ratio of Ni NWs have no regular impact on the saturation magnetization and the squareness of Ni NWs. The Hc of Ni NWs was, however, a function of the aspect ratio rather than diameter, which is different from that of Ni NWs prepared by template method. The variation of Hc of Ni NWs can be described using the chain-of-sphere model. (C) 2016 Elsevier B.V. All rights reserved.