Magnetic and thermodynamic properties of Nd3NiGe2

We here report the magnetization, M, and specific heat, C, of ${\mathrm{Nd}}_3{\mathrm{NiGe}}_2$, which crystallizes in the orthorhombic ${\mathrm{Gd}}_3{\mathrm{NiSi}}_2$-type structure. Nd ions occupy three nonequivalent sites in a unit cell. Upon cooling, magnetization divided by magnetic field, $M/B$, increased sharply at the Curie temperature, $T_C$, of 87 K and below 40 K. The former result indicates that the increase in $M/B$ observed at $T_C$ is due to the long-range ferromagnetic order. The increase below 40 K is derived from a short-range correlation because of the absence of clear anomaly in $C\left(T\right)$. At 10 K and 2 K, the values of M undergo metamagnetic transitions. The value of magnetic specific heat divided by temperature shows a shoulder-like anomaly at around 20 K, which is attributed to antiferromagnetic behavior. Furthermore, two peaks in $C\left(T\right)$ were observed at 4.5 K and 3.8 K, and these peaks occurred at lower temperatures in the presence of a magnetic field. This behavior is typical of materials with antiferromagnetic order. These observations are attributed to the competition between ferromagnetic and antiferromagnetic interactions, which is a result of the three nonequivalent Nd sites.