Magnetic ground state of Dy3+ in DyNiAl4

Abstract

Previously, the bulk magnetisation of polycrystalline DyNiAl4 was found to reach barely half its expected saturation value with a 9 T applied field. New inelastic neutron scattering and 161Dy-Mössbauer spectroscopy results suggest that the crystal field splitting for Dy3+ in DyNiAl4 is dominated by B20 with a low temperature local Dy3+ moment close to its full free-ion value of ± 10 μB. Considering that the magnetization for related single crystal specimens (e.g. for TbNiAl4) typically grows more rapidly with the applied field directed along the easy axis, the slower response for DyNiAl4 powder must be due to a strong magneto-crystalline anisotropy hindering the moment realignment.