  In this paper, we report the growth of NaxCoO2 thin films by pulsed-laser
deposition (PLD). It is shown that the concentration of sodium is very
sensitive to the substrate temperature and the target-substrate distance due to
the evaporation of sodium during the deposition. alpha prime-phase Na0.75CoO2
and gamma- phase Na0.71CoO2 thin films can be obtained with different
conditions. Correspondingly, the surface morphology of the films changes from
flake-like to particle-like. The temperature dependence of resistivity for the
films prepared with the optimal condition shows metallic behavior, consistent
with the data of NaxCoO2 single crystals. This work demonstrates that PLD is a
promising technique to get high quality NaxCoO2 thin films.
