Paramagnetic form factors from itinerant electron theory

A uniform magnetic field induces in a non-magnetic metal a magnetization density which has the periodicity of the lattice. The bulk susceptibility is proportional to the average of the moment density, and the magnetic form factor as measured by the polarized neutron scattering technique gives the Fourier transform of the moment distribution. The authors have developed a different method to evaluate approximately the orbital part of the bulk susceptibility. The method is based on two observations: (1) that the largest contribution to the sum comes from states near the Fermi level, and in transition metals these are largely d states; and (2) that the dipole matrix elements between states in the d bands are very small