| Abstract
| - We report an electrochemical synthesis of two-dimensionally ordered porous Ni arrays based on polystyrenesphere (PS) colloidal monolayer. The morphology can be controlled from bowl-like to hollow sphere-likestructure by changing deposition time under a constant current. Importantly, such ordered Ni arrays on aconducting substrate can be transferred integrally to any other desired substrates, especially onto an insultingsubstrate or curved surface. The magnetic measurements of the two-dimensional hollow sphere array showthe coercivity values of 104 Oe for the applied field parallel to the film, and 87 Oe for the applied fieldperpendicular to the film, which is larger than those of bulk Ni and hollow Ni submicrometer-sized spheres.The formation of hollow sphere arrays is attributed to preferential nucleation on the interstitial sites betweenPS in the colloidal monolayer and substrate, and growth along PSs' surface. The transferability of the arraysoriginates from partial contact between the Ni hollow spheres and substrate. Such novel Ni orderednanostructured arrays with transferability and high magnetic properties should be useful in applications suchas data storage, catalysis, and magnetics.
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