The magnetic structure of DyMn₂

Abstract

The evolution with temperature of the magnetic structure of the C15 Laves-phase compound DyMn2 has been studied using powder neutron diffraction and magnetization techniques. The Dy sublattice assumes a spin-canted ferromagnetic structure with 8.8 mu B per Dy atom. Although all Mn sites within the unit cell are chemically equivalent, only one Mn atom in four is found to possess a magnetic moment (of 1.4 mu B). These magnetic Mn atoms are located at sites with a strongly polarizing magnetic environment resulting from a near-neighbour configuration of ferromagnetically coupled Dy spins. A spin reorientation is observed at 36 K, and is accompanied by a small thermal expansion anomaly. The Curie temperature of DyMn2 is found to be 45 K.