Synthesis and magnetic properties of nickel ferrite nano-octahedra

High yield of nickel ferrite nano-octahedra with size distribution from 40 to 90 nm were synthesized through a simple hydrothermal method. The formation of faceted octahedra enclosed by {111} planes implies the much faster growth rate along 〈100〉 over 〈111〉 for face-centered cubic phase during hydrothermal process. Magnetic measurements indicated that the sample is soft-magnetic materials with much lower coercivity and much higher saturation magnetization compared to the nickel ferrite nano-crystals with similar size distribution but irregular shapes reported earlier.