  We report on the growth of NdFeAs(O,F) thin films on [001]-tilt MgO bicrystal
substrates with misorientation angle theta_GB=6{\deg}, 12{\deg}, 24{\deg} and
45{\deg}, and their inter- and intra-grain transport properties. X-ray
diffraction study confirmed that all our NdFeAs(O,F) films are epitaxially
grown on the MgO bicrystals. The theta_GB dependence of the inter-grain
critical current density Jc shows that, unlike Co-doped BaFe2As2 and Fe(Se,Te),
its decay with theta_GB is rather significant. As a possible reason of this
result, fluorine may have diffused preferentially to the grain boundary region
and eroded the crystal structure.
