Crystal and magnetic properties of Er5Ni2In4 at low temperatures

The Er5Ni2In4 compound belongs to a novel family of rare earth-based intermetallics crystallizing within the Lu5Ni2In4-type structure (Pbam Space group). In this paper we report results of structural as well as magnetic studies including X-ray diffraction (between 12 and 300 K); neutron diffraction (between 1.5 and 24 K), magnetometric and calorimetric data (in 2–300 K temperature range). The Er3+ ions occupy three crystal positions within the unit cell: two 4g sites and the 2a site. According to results of neutron diffraction, the Er magnetic moments at 4g sites form a non-collinear magnetic structure below 18.5 K. Additional magnetic transition at about 2 K, originating in ordering of the 2a sublattice, occurs as well. In addition, magnetic entropy derived on the basis of specific heat studies is discussed yielding the doublet crystal field ground states for each of the sublattices.