Anisotropic magnetic properties of RE2CoIn8 (RE=Pr, Nd, Dy) compounds

Single crystals of Pr2CoIn8, Nd2CoIn8 and Dy2CoIn8 have been successfully prepared for the first time and investigated by means of magnetization measurements. Anisotropy of the magnetic properties has been observed. The paramagnetic susceptibility data are interpreted in conjunction with results of first-principles calculations of the crystal-field parameters. The disagreement between the experimental paramagnetic Curie temperature values for the magnetic field applied along the a- and c-axis and the corresponding results of calculations for Pr2CoIn8 and Nd2CoIn8 can be attributed to a limited validity of the single-particle crystal-field interaction. The Van Vleck paramagnetism of Pr2CoIn8 has been confirmed. The experimental data collected for Nd2CoIn8 and Dy2CoIn8 point to antiferromagnetic ordering below TN=9.6 and 16.7 K, respectively. It is shown that Nd2CoIn8 undergoes two metamagnetic transitions at low temperatures in a field applied along the c-axis whereas the paramagnetic response at the perpendicular field demonstrates uniaxial magnetocrystalline anisotropy. Two metamagnetic transitions have been observed also in Dy2CoIn8. In this case, however, a metamagnetic transition can be induced also in magnetic fields applied within the basal plane. Comparing the properties of presented materials with the variety of other REnTIn3n+2 compounds certain features appear being universal across the series of their isostructural analogs.