Abstract

We report on the superconducting properties of nanocrystalline molybdenum nitride thin films grown by reactive DC sputtering at room temperature with a N-2:Ar mixture. Thin films grown using 5% N-2 concentration display T-c = 8 K, which is gradually reduced to 5.8 K for 30% N-2 concentration, producing changes in nitrogen stoichiometry of the samples from Mo2N to Mo2N1+x (0 = x 0.4). The T-c is abruptly reduced and disappears for N-2 concentration between 30% and 40%, which can be attributed to an increment in the disorder due to phase coexistence between cubic gamma-Mo2N and non-superconducting amorphous MoN (dominant for N-2 concentration >40%). (C) 2017 Elsevier B.V. All rights reserved.