Approach to Magnetic Saturation in the Vicinity of Impurity Atoms

Ritz-method calculations are used to estimate the angles between applied magnetic fields of the order of ${10}^3$ Oe and the magnetization in the vicinity of W or Nd impurity atoms in Fe or Ni. It is assumed that the impurity atom is substitutional and that its main effect is the magnetostriction, due to the mechanical strain caused by introducing an atom having a different size from that of the other atoms in the lattice, but it is shown that magnetostatic effects, caused by introducing a nonmagnetic atom, might also be important. Radii of free atoms are used, and because of this and other approximations used in the calculations of the various energy terms, the theoretical angles are only a crude approximation; but they do come to within a factor of 2 or so of the experimentally measured angles.