Abstract
The mechanism of stress relaxation in nanocrystalline Fe-N thin film has been studied. The as-deposited film possesses a strong in-plane compressive stress which relaxes with thermal annealing. Precise diffusion measurements using nuclear resonance reflectivity show that stress relaxation does not involve any long-range diffusion of Fe atoms. Rather, a redistribution of nitrogen atoms at various interstitial sites, as evidenced by conversion electron Mössbauer spectroscopy, is responsible for the relaxation of internal stresses. On the other hand, formation of the -FeN phase at temperatures above 523 K involves long-range rearrangement of Fe atoms. The activation energy for Fe self-diffusion is found to be eV.
5 More- Received 30 December 2011
DOI:https://doi.org/10.1103/PhysRevB.85.075401
©2012 American Physical Society