Superconductivity in SrNi2As2 single crystals

The electrical resistivity rho(T) and heat capacity C(T) on single crystals of SrNi2As2 and EuNi2As2 are reported. While there is no evidence for a structural transition in either compound, SrNi2As2 is found to be a bulk superconductor at T-c=0.62 K with a Sommerfeld coefficient of gamma=8.7 mJ/mol K-2 and a small upper critical field H-c2 similar to 200 Oe. No superconductivity was found in EuNi2As2 above 0.4 K, but anomalies in rho and C reveal that magnetic order associated with the Eu2+ magnetic moments occurs at T-m=14 K.