Superconductivity and spin fluctuations in the electron-doped infinitely-layered high Tc superconductor Sr0.9La0.1CuO2 (Tc = 42 K)

We report 63Cu NMR studies on uniaxially aligned and unaligned powder samples of an electron-doped infinitely-layered high Tc cuprate superconductor Sr0.9La0.1CuO2 (Tc = 42 K). We measured the nuclear spin-lattice relaxation rate 1T1 up to 800 K. We found from the temperature dependence of 1T1 T that the wave-vector-averaged spin susceptibility is highly enhanced by spin-fluctuations in the normal state, resulting in a Curie-Weiss behavior. Below Tc, we did not observe a Hebel-Slichter coherence peak of 1T1, suggesting an unconventional nature of the symmetry of the superconducting order parameter. These results are quite similar to those observed for some hole-doped high Tc cuprates.