OICC Press Journal of Nanostructure in Chemistry 2193-8865 3 1 (December 2013) 2013 02 25 Annealing temperature effect on the mechanical and tribological properties of molybdenum nitride thin films 10.1186/2193-8865-3-5 EN Kaykhosrow Khojier Department of Physics, Chalous Branch, Islamic Azad University, Chalous, 46615-397, IR Mohammad Reza Karami Mehr Department of Physics, Faculty of Science, Central Tehran Branch, Islamic Azad University, Tehran, 13185-786, IR Hadi Savaloni Department of Physics, University of Tehran, Tehran, 14395-515, IR Journal Article 2013 02 25 Abstract Mo thin films with 100-nm thickness were deposited on silicon substrates using DC magnetron sputtering method. Mo thin films were subsequently annealed at different temperatures (400°C to 900°C) with flow of nitrogen. The crystallographic structure of the samples was obtained using X-ray diffraction method. Atomic force microscopy and scanning electron microscopy were used for surface morphology investigation. Nano-indentation and scratch tests were performed to obtain the surface hardness and friction coefficient of the samples, respectively. Results show that the γ -Μο 2 Ν(111) phase of molybdenum nitride with face-centered cubic structure and higher hardness, elastic modulus, and lower coefficient of friction and scratch volume is formed when the sample is annealed at 650°C, while the Mo 2 N phase with tetragonal structure and lower hardness, elastic modulus, and higher scratch volume and friction coefficient is formed at higher temperatures of 775°C and 900°C. It is found that increasing the annealing temperature causes an increase of the grain size and film surface roughness. From the mechanical results, it may be deduced that 650°C is a critical temperature for variation of mechanical and tribological properties.