Microscopic magnetic ground state and metamagnetic-transition origin in LuInCo4

Determine the microscopic magnetic ground state of LuInCo4 and establish the origin of its low-temperature metamagnetic transition.

Background

LuInCo4 is a cobalt-based C15b Laves-phase compound with a pyrochlore Co sublattice. It undergoes ferromagnetic ordering near 306 K, develops magnetic anisotropy with [001] as the easy magnetization axis below approximately 100 K, and exhibits a low-field metamagnetic transition when a magnetic field is applied along the hard [111] direction.

The paper investigates this unresolved issue using powder and single-crystal neutron diffraction. The reported data support a collinear ferromagnetic structure with propagation vector q=0 and reveal temperature-dependent diffuse magnetic scattering interpreted as evidence for gradual localization of itinerant Co–3d electrons. However, the measurements do not fully establish the microscopic origin of the metamagnetic transition or definitively resolve all aspects of the magnetic ground state.