Correlative plasma-surface model for metastable Cr-Al-N: Frenkel pair formation and influence of the stress state on the elastic properties
Music, D. and Banko, L. and Ruess, H. and Engels, M. and Hecimovic, A. and Grochla, D. and Rogalla, D. and Brögelmann, T. and Ludwig, A. and Von Keudell, A. and Bobzin, K. and Schneider, J.M.
JOURNAL OF APPLIED PHYSICS
Volume: 121 Pages:
Correlatively employing density functional theory and experiments congregated around high power pulsed magnetron sputtering, a plasma-surface model for metastable Cr0.8Al0.2N (space group Fm 3 m) is developed. This plasma-surface model relates plasma energetics with film composition, crystal structure, mass density, stress state, and elastic properties. It is predicted that N Frenkel pairs form during Cr0.8Al0.2N growth due to high-energy ion irradiation, yielding a mass density of 5.69 g cm-3 at room temperature and Young's modulus of 358-130 GPa in the temperature range of 50-700 K for the stress-free state and about 150 GPa larger values for the compressive stress of 4 GPa. Our measurements are consistent with the quantum mechanical predictions within 5% for the mass density and 3% for Young's modulus. The hypothesis of a stress-induced Young's modulus change may at least in part explain the spread in the reported elasticity data ranging from 250 to 420 GPa. © 2017 Author(s).