We report the first 17-O NMR studies of a triangular-lattice superconductor Na{ 1/3}CoO{ 2}-[4/3]H{ 2}O and the host material Na{ x}CoO{ 2} (x=0.35 and 0.72). Knight shift measurements reveal that p-d hybridization induces sizable spin polarization in the O triangular-lattice layers. Water-intercalation makes CoO{ 2} planes homogeneous, and enhances low frequency spin fluctuations near T{ c}=4.5 K at some finite wave-vectors different from both the ferromagnetic and ``120 degree'' modes.
Categories: cond-mat.str-el cond-mat.supr-con