  We report on the superconducting properties of molybdenum nitride thin films
grown by reactive DC sputtering at room temperature with a N2:Ar mixture. Thin
films grown using 5 % N2 concentration display Tc = 8 K, which is gradually
reduced and abruptly disappears for 40 % N2 concentration. This suppression can
be associated with changes in the nitrogen stoichiometry from Mo2N to MoN. Our
results provide an effective and simple path to prepare Mo2Nx thin films with
tunable Tc, which is relevant for the investigation of the fundamental
properties and for technological applications.
