Pairing Of Weakly Correlated Electrons In The Platinum-Based Centrosymmetric Superconductor Srpt3p

We report a study of the normal- and superconducting-state electronic properties of the centrosymmetric compound SrPt3P via P-31 nuclear-magnetic-resonance (NMR) and magnetometry investigations. Essential features such as a sharp drop of the Knight shift at T < T-c and an exponential decrease of the NMR spin-lattice relaxation ratio 1/(T1T) below T-c are consistent with an s-wave electron pairing in SrPt3P, although a direct confirmation in the form of a Hebel-Slichter-type peak is lacking. Normal-state NMR data at T < 50 K indicate conventional features of the conduction electrons, typical of simple metals such as lithium or silver. Our data are finally compared with available NMR results for the noncentrosymmetric superconductors LaPt3Si and CePt3Si, which adopt similar crystal structures.