Competing magnetism and superconductivity in Na(x)CoO2 at half doping.
We report the effect of topotactic replacement of Na(+) by H(3)O(+) in Na(0.5)CoO(2). Hydronium ions keep the Co oxidation state constant, increasing the interlayer distance. The result is a progressive destruction of the spin density wave characteristic of half-doped Na(x)CoO(2) and ultimately the induction of superconductivity. This implies that superconductivity occurs closer to Co(3+)/Co(4+) approximately = 1 than previously thought and that its development competes with the development of the magnetic phase.
Bañobre-López
Manuel
M
Department of Physical Chemistry, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain.
Rivadulla
Francisco
F
López-Quintela
M Arturo
MA
Rivas
José
J