Magnetic Form Factor of Elastic Neutron Scattering Expected for Octupolar Phases in Ce_<1-χ>La_χB_6 and NpO_2(Condensed matter: electronic structure and electrical, magnetic, and optical properties)

概要

論文の詳細を見る
Elastic neutron scattering spectra expected for ordered magnetic octupoles are studied theoretically for Ce_<1-χ>La_χB_6 and NpO_2. Assuming the order parameter deduced from the resonant X-ray scattering and NMR experiments, we have calculated spin and orbital parts of the magnetic form factors using the radial wave function for the single f-electron state in the Ce and Np ions. The octupolar contributions to the form factor at the superlattice spots are shown to be quite small in the long wave-length region, whereas it becomes markedly enhanced for short wave lengths. We discuss how and to what extent the intensity due to octupoles in short wave length is developed, and whether it is observable in experiments. The anisotropy of the form factor is discussed in connection with the symmetry aspect of the neutron cross section due to octupoles. In the case of Ce_<l-χ>La_χB_6, it is shown that the calculated results are consistent with recent observations by Kuwahara et al., thus confirming for the first time the existence of the ordered octupole by neutron scattering.
社団法人日本物理学会の論文
2007-09-15