Polarized neutron diffraction study of CoS2, 1

The magnetic form factor of CoS2 has been determined for 27 Bragg reflections by means of the polarized neutron diffraction technique. Fourier transform of the observed data shows that the magnetic moment is localized on cobalt atoms, and the moment distribution is aspherical around cobalt nuclei, and there is almost no magnetic moment delocalized in the region between cobalt atoms. The measured magnetic form factor agrees well with the calculated free ion form factor for Co2+. The comparison between calculated and measured magnetic form factors shows that the magnetic moment delocalized in the region between cobalt atoms is very small, 0.013+-0.024 (μsub(B)/CoS2), compared with those in ferromagnetic 3d-transition metals. It shows further that 69+-4% of the unpaired 3d electrons occupy esub(g) orbitals on the basis of the point charge model for the cubic crystalline field. (auth.)