Research articlesControllable preparation of iron nanostructures and their magnetic properties

•Simple adjustable method has been achieved to control nano-Fe magnetic properties.•Fe chains can be changed into particles under certain concentration of NaOH and PVP.•Magnetic properties of Fe chains are influenced by particle size via dispersants.•Coercivity and saturation of Fe chains is higher than that of Fe nanoparticles.

Iron nanostructures (chains and particles) were prepared by a simple reduction method. The effects of adding NaOH, PEG or PVP, changing c(Fe2+) can lead to different results of microstructure on iron nanochains/nanoparticles. The directional controlled preparation was researched. Their magnetic properties at normal (300 K) and low (5 K) temperatures have been measured, and influences of OH−, polymeric dispersant PEG/PVP, and c(Fe2+) have been investigated in detail. The magnetic properties of nanochains/nanoparticles were studied by controllable microstructure through the adjustment of sort of dispersant and ferrous concentration, which can accomplish the fabrication in accordance with magnetism applications.