Neutron Scattering Studies of Pyrochlore Compound Nd2Mo2O7 in Magnetic Field

TL;DR

This study uses neutron diffraction to analyze the magnetic structure of Nd2Mo2O7 under magnetic fields, revealing that the chiral order mechanism does not explain its Hall resistivity behavior.

Contribution

It provides detailed magnetic structure analysis under magnetic fields and tests the applicability of the chiral order mechanism to Nd2Mo2O7.

Findings

Magnetic reflections change with magnetic field and temperature.

Chiral order mechanism does not explain Hall resistivity in Nd2Mo2O7.

Magnetic structure modeling accounts for exchange interactions and anisotropies.

Abstract

Neutron diffraction studies have been carried out in the applied magnetic field H(//[011]) on a single crystal of pyrochlore ferromagnet Nd2Mo2O7, whose Hall resistivity(r_H) has been reported to have quite unusual magnetic field (H)- and temperature (T)- dependences. The intensities of the observed magnetic reflections have been reproduced at 1.6 K as a function of H, by considering the change of the magnetic structure with H, where effects of the exchange fields at the Mo and Nd sites induced by the Mo-Mo and Mo-Nd exchange interactions and the single ion anisotropies of Mo- and Nd- moments are considered. From the H-dependent magnetic structure, the H-dependence of r_H has been calculated by using the chiral order mechanism. By comparing the result with the H-dependence of the observed r_H, it is found that the chiral order mechanism does not work well in the present system.