Conducting transition metal nitride thin films with tailored cell sizes: The case of δ- Tix Ta1-x N - Koutsokeras, L.E.; Abadias, G.; Lekka, Ch.E.; Matenoglou, G.M.; Anagnostopoulos, D.F.; Evangelakis, G.A.; Patsalas, P. (Applied Physics Letters, 2008)