  The observation of superconductivity at 4.3 K in a new crystalline form of
Na0.3CoO2*1.3H2O is reported. The new superconductor has three layers of CoO6
octahedra per crystallographic unit cell, in contrast to the previously
reported two-layer superconductor. The three-layer cell occurs because the
relative orientations of neighboring CoO2 layers are distinctly different from
what is seen in the two-layer superconducting phase. This type of structural
difference in materials that are otherwise chemically and structurally
identical is not possible to attain on the layered copper oxide
superconductors. The synthesis and stability of the new phase are described.
