Abstract
The dependence of the magnetic properties of 200-Å-diam elongated particles of iron on cobalt alloy content is reported over the range from 0% to 90% cobalt. In particular, the compositional dependence of coercive force, corrected to zero packing density, is examined and compared to that expected theoretically for shape anisotropy. To a first approximation theory and experiment agree. Differences between theory and experiment in the compositional behavior of coercive force as well as temperature coefficient of coercive force and coercive force change with packing are attributed to a small crystal anisotropy contribution. However, the crystal anisotropies required do not agree with bulk measurements. Magnet energy was constant and at a maximum from 20 to 70% cobalt rather than only at 38% cobalt as predicted from considering shape anisotropy energy alone.