Magnetic form factor of nickel

The magnetic form factor of Ni is calculated using the pseudopotential method, the ferromagnetic interaction being supplied by a parametrized Hubbard - Kanamori Hamiltonian. This approach is useful in the present instance because the form factor is primarily determined by uncompensated majority spin electrons near the Fermi surface where LCAO d-band functions represent a reasonable approximation for the wave functions. The asphericity of the d-electron spin distribution as well as the constant negative polarization of electrons in the outer regions of the unit cell observed by Mook and Shull are reproduced. The latter effect is accounted for by a reversal of the s-spin polarization in that region of the unit cell. A possible contribution due to a slow spatial variation of the spin polarization over the unit cell associated with compensated d electrons throughout the d band is also discussed.