Correlation between Superconducting Transition Temperature $T_c$ and Increase of Nuclear Spin-Lattice Relaxation Rate Devided by Temperature $1/T_{1}T$ at $T_c$ in the Hydrate Cobaltate Na${}_x$CoO${}_2\cdot y$H${}_2$O

Y. Ihara, K. Ishida, C. Michioka +6

We have performed Co-nuclear quadrupole resonance (NQR) studies on Na${}_x$CoO${}_2\cdot y$H${}_2$O compounds with different Na ($x$) and hydrate ($y$) contents. Two samples with d…