Studies of Anomalous Hall Effect and Magnetic Structure of Nd2Mo2O7 –Test of Chirality Mechanism–

The unusual behavior of the anomalous Hall resistivity ρ H found in the pyrochlore oxide Nd 2 Mo 2 O 7 is re-analyzed. There are mainly two kinds of qualitatively interpretation of the observed behavior, one based on an idea that the ρ H of this system is induced by the chirality ordering of the Mo spins and the other based on a phenomenological expression found by the present authors' group that the ρ H of the system is described as the summation of the contributions from the Mo and Nd moments. Because even after the publication of our results based on the magnetic structure analyses under the external magnetic field H , that the chirality mechanism cannot be considered to be the primary origin of the unusual behavior, the non-applicability of the mechanism still seems not to be completely fixed, we have taken further data of neutron scattering and used them, in the present analyses, together with published specific heat data and various other ones, which were also used in the previous analyses. Introduc...