  Bulk superconductivity was discovered in BaRh2P2 (Tc = 1.0 K) and BaIr2P2 (Tc
= 2.1 K), which are isostructural to (Ba,K)Fe2As2, indicative of the appearance
of superconductivity over a wide variety of layered transition metal pnictides.
The electronic specific heat coefficient gamma in the normal state, 9.75 and
6.86 mJ/mol K2 for BaRh2P2 and BaIr2P2 respectively, indicate that the
electronic density of states of these two compounds are moderately large but
smaller than those of Fe pnictide superconductors. The Wilson ratio close to 1
indeed implies the absence of strong electron correlations and magnetic
fluctuations unlike Fe pnictides.
