Synthesis and magnetic properties of nickel nanoparticles deposited on the silicon nanowires

Nickel (Ni) nanoparticles with sizes of ∼35 nm were deposited on the surface of silicon nanowires (SiNWs) by electroless plating technique. The magnetic properties of Ni/SiNWs were investigated. The blocking temperature (TB) of 370 K was obtained and confirmed by field-cooled (FC) and zero-field-cooled (ZFC) plots. The M–H hysteresis loops from 5 K to 400 K were measured. The saturation magnetization value was ∼4.5 emu/g and the coercivity was ∼375.3 Oe for the loop at 5 K, respectively. While for the loop at 400 K, these values were of ∼2.6 emu/g and ∼33.3 Oe, respectively. The temperature dependence of coercivity followed by the relation HC(T) = HC0[1 − (T/TB)1/2], indicating a superparamagnetic behavior. The magnetization of superparamagnetic grains in a magnetic field H was better described by Langevin function at 400 K. These novel magnetic properties of Ni/SiNWs were possibly attributed to the paramagnetic defects on the surface of SiNWs.

Ni nanoparticles (∼35 nm) were deposited on SiNWs by electroless plating technique. The magnetic properties of Ni/SiNWs are investigated. The superparamagnetic characteristic is observed above 370 K.Figure optionsDownload as PowerPoint slideHighlights
► Ni nanoparticles (∼35 nm) were deposited on SiNWs by electroless plating technique.
► The as-grown SiNWs revealed several paramagnetic defects.
► The magnetic properties of Ni/SiNWs are investigated.
► The superparamagnetic characteristic is observed above 370 K.