Nanostructures of Ni and NiCo Amorphous Alloys Synthesized by a Double Composite Template Approach

Two-dimensional handkerchief-like nanostructures of Ni and NiCo magnetic amorphous alloys have been synthesized by a double composite structure-inducing template. High resolution transmission electron microscopy was used to characterize the morphology and the dimensions. The self-assembly of fine handkerchief-like Ni and NiCo nanoalloys is attributed to the cooperation between ion-selected delivery of a hard collodion membrane by nitro-group chemical complexations and the size-controlled action of a reverse microemulsion. Importantly, the coordinations of ethylenediamine with Ni2+ and Co2+ can restrict the structure-inducing action. The phase transformation behavior was recorded by differential scanning calorimetry. Substituting Co for Ni can slow phase transformation, and the kinetic ordering temperature increases with the Co concentration increasing. The magnetic property measurement results show that the saturation magnetizations increase as the Co concentration is increased, but the coercivity is not sensitive to the Co concentration and is decided only by the phase structure.