Determination of the ferrimagnetic structure of monoclinic TbFe$_{2}$D$_{4.2}$ deuteride and its evolution versus temperature and high magnetic field

Abstract

The magnetic properties of monoclinic TbFe$_{2}$D$_{4.2}$ have been investigated by combining different magnetic measurements, including those involving a high pulsed magnetic field, with neutron diffraction experiments versus temperature and applied field. TbFe$_{2}$D$_{4.2}$ displays a ferrimagnetic ground state with M$_{Tb}$ = 8.2(2) $μ$$_{B}$ and M$_{Fe}$ = 2.1(2) $μ$$_{B}$. At 4.2 K a large magnetic anisotropy related to the Tb moments is observed, as saturation is not reached at 50 T. In addition, two metamagnetic transitions are observed for fields of 3 and 29 T. Upon heating, the Tb moment decreases progressively whereas the Fe moment remains constant up to 150 K. At 160 K both Tb and Fe moments sharply decrease, and a 0.38% contraction of the cell volume is observed due to an itinerant electron metamagnetic behavior of the Fe sublattice. This transition temperature is 76 K higher than that of YFe$_{2}$D$_{4.2}$ due to an increase in cell volume, as well as exchange interactions between the Fe and Tb moments. The deuteride becomes paramagnetic above 220 K.