The electrical resistivity $\rho \left(T\right)$ and heat capacity $C\left(T\right)$ on single crystals of ${\text{SrNi}}_2{\text{As}}_2$ and ${\text{EuNi}}_2{\text{As}}_2$ are reported. While there is no evidence for a structural transition in either compound, ${\text{SrNi}}_2{\text{As}}_2$ is found to be a bulk superconductor at $T_c=0.62\text{K}$ with a Sommerfeld coefficient of $\gamma =8.7\text{mJ}/\text{mol}{\text{K}}^2$ and a small upper critical field $H_{c2}\sim 200\text{Oe}$. No superconductivity was found in ${\text{EuNi}}_2{\text{As}}_2$ above 0.4 K, but anomalies in $\rho$ and $C$ reveal that magnetic order associated with the ${\text{Eu}}^{2+}$ magnetic moments occurs at $T_m=14\text{K}$.

• Received 6 August 2008

DOI:https://doi.org/10.1103/PhysRevB.78.172504