Study of the Low-temperature Magnetic Structure of the 5d Transition Metal Pyrochlore Oxide

Abstract

Cd₂Os₂O₇ shows a metal-insulator transition at 227 K with magnetic ordering in an undistorted pyrochlore lattice, but its magnetic structure and the origin of the transition are not yet uncovered. We observed commensurate magnetic peaks by resonant X-ray scattering experiments on a high-quality single crystal. A noncollinear all-in/all-out spin arrangement on the Os tetrahedra is proposed on the bases of the experimental results and the irreducible representation analysis.