화학공학소재연구정보센터
Applied Surface Science, Vol.368, 88-96, 2016
Temperature-dependent microstructural evolution of Ti2AlN thin films deposited by reactive magnetron sputtering
Ti2AlN MAX-phase thin films have been deposited on MgO (111) substrates between 500 and 750 degrees C using DC reactive magnetron sputtering of a Ti2Al compound target in a mixed N-2/Ar plasma. The composition, crystallinity, morphology and hardness of the thin films have been characterized by X-ray photoelectron spectroscopy, X-ray diffraction, atomic force microscopy and nano-indentation, respectively. The film initially forms a mixture of Ti, Al and (Ti, Al)N cubic solid solution at 500 degrees C and nucleates into polycrystalline Ti2AlN MAX phases at 600 degrees C. Its crystallinity is further improved with an increase in the substrate temperature. At 750 degrees C, a single-crystalline Ti2AlN (0002) thin film is formed having characteristic layered hexagonal surface morphology, high hardness, high Young's modulus and low electrical resistivity. The mechanism behind the evolution of the microstructure with growth temperature is discussed in terms of surface energies, lattice mismatch and enhanced adatom diffusion at high growth temperatures. (C) 2016 Elsevier B.V. All rights reserved.