Some Magnetic Properties and Magnetocaloric Effects in the High-Temperature Antiferromagnet YbCoC2

Abstract

The YbCoC2 compound, which crystallizes in a base-centered orthorhombic unit cell in the Amm2 space group CeNiC2 structure, is unique among Yb-based compounds due to the highest magnetic ordering temperature of TN=27 K. Magnetization measurements have made it possible to plot the H-T magnetic phase diagram and determine the magnetocaloric effect of this recently discovered high-temperature heavy-fermion compound, YbCoC2. YbCoC2 undergoes spin transformation to the spin-polarized state through a metamagnetic transition in an external magnetic field. The transition is found to be of the first order. The dependencies of magnetic entropy change ΔSm(T)—have segments with positive and negative magnetocaloric effects for ΔH≤6 T. For ΔH=9 T, the magnetocaloric effect becomes positive, with a maximum ΔSm(T) value of 4.1 J (kg K)−1 at TN and a refrigerant capacity value of 56.6 J kg−1.