Shape Anisotropy Evolution of Co Grains in Cu-30at%Co Alloy by Annealing under Magnetic Field

Abstract

The shape change of the fcc-Co grains during the coarsening process was examined by using the Cu30at%Co alloys. The fine Co-rich particles were uniformly distributed in the rapidly solidified alloys when the cooling rate was sufficiently large to prevent the dendritic growth of the primary Co phase. The influence of the magnetic field on the shape change of the Co grains was clearly observed when the rapidly solidified particles were annealed at 1 173 K under 10 T. The average angle between the long-axis and the magnetic field direction at 10 T is 15 degrees smaller than the average value at 0 T. The coarsening model suggested that the shape magnetic anisotropy energy acts as a driving force of the coarsening in the region that the Co grain size is several mm. The static magnetic energy due to the shape anisotropy has an alternative potential to produce the aligned structure.