Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10620564 | Acta Materialia | 2011 | 10 Pages |
Abstract
Thermal treatment of supersaturated Ti1âxAlxN films (x â 0.67) with a dominant ternary cubic-phase were performed in the 700-1000 °C range. Grazing incidence X-ray diffraction (GIXRD) shows that, for annealing temperatures up to 800 °C, the film structure undergoes the formation of coherent cubic AlN (c-AlN) and TiN (c-TiN) nanocrystallites via spinodal decomposition and, at higher temperatures (⩾900 °C), GIXRD shows that the c-AlN phase transforms into the thermodynamically more stable hexagonal AlN (h-AlN). X-ray absorption near-edge structure (XANES) at the Ti K-edge is consistent with spinodal decomposition taking place at 800 °C, while Al K-edge and N K-edge XANES and X-ray emission data show the nucleation of the h-AlN phase at temperatures >800 °C, in agreement with the two-step decomposition process for rock-salt structured TiAlN, which was also supported by X-ray diffraction patterns and first-principle calculations. Further, the resonant inelastic X-ray scattering technique near the N K-edge revealed that N2 is formed as a consequence of the phase transformation process.
Keywords
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
J.L. Endrino, C. Ã
rhammar, A. Gutiérrez, R. Gago, D. Horwat, L. Soriano, G. Fox-Rabinovich, D. MartÃn y Marero, J. Guo, J.-E. Rubensson, J. Andersson,