MAGNETIC-PROPERTIES OF HIGH-PURITY NANOCRYSTALLINE NICKEL

High purity nanocrystalline Ni has been prepared by means of the inert gas condensation technique with oxygen contents of less than 0.5 at% compared to 6 at% after exposure to air. In-situ magnetic measurements with the specimens sealed in vials under vacuum indicate that the sat uration magnetization, of high purity nanocrystalline Ni is unchanged compared to the bulk value but reduced to similar to 80% of the bulk v alve in specimens which were exposed to air. The magnetization process in nanocrystalline Ni changes from a homogeneous rotation in powder s pecimens to domain wall movement in specimens after compaction where m agnetic domains are observed by means of magneto-optic Kerr techniques .