The specific heat of single crystal NdCu2

We present the measurements of the specific heat C of NdCu2 on single crystal samples of high purity in the temperature range between 0.7 K and 70 K. We observed three peaks: two are first order peaks at T-R1 = 3.97 K and T-R2 = 4.22 K and one is the antiferromagnetic transition at T-N = 6.50 K. The gap in the density of state of the antiferromagnetic spin wave band is found below T-R2. The specific heat observed below T-R1 is well expressed by the gap type formula C = gamma T + beta T-m(3) exp(-delta/k(B)T). We show good correlation between the entropies of NdCu2 and the magnetic resistivity measured along the crystal b-axis.