Spin Density on B Sites and Magnetic Structure Factors of CeB6

Structure factors for magnetic scattering of neutrons by CeB 6 are calculated for the magnetic moment distributions at 1.5 K and 8 T (in phase II) determined from the analysis of the hyperfine field at B nuclei. 4 f electrons of Ce are polarized magnetically with the magnetic moment of about 1µ B per Ce parallel to the applied field, whereas 2 p electrons of B are also polarized inversely by about -0.1µ B per B 6 molecule. The structure factor S ( Q ) has a large anisotropy for the direction of the scattering vector Q due to the anisotropy of the 4 f wave function. For small Q , an oscillatory feature appears in S ( Q ) due to the inhomogeneous spin densities on the 2 p states of B sites. Diffraction peaks with half-integer indexes are predicted to appear in the large Q region, which will provide direct evidence of the antiferro-octupolar ordering induced by a magnetic field in phase II.