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Spectral evidence of spinodal decomposition, phase transformation and molecular nitrogen formation in supersaturated TiAlN films upon annealing

Authors

ENDRINO ARMENTEROS, JOSÉ LUIS, Rhammar C. , Gutiérrez A. , Gago R. , Horwat D. , Soriano L. , Fox-Rabinovich G. , Martín Y Marero D. , Guo J. , Rubensson J.-E. , Andersson J.

External publication

Si

Means

Acta Mater.

Scope

Article

Nature

Científica

JCR Quartile

SJR Quartile

JCR Impact

3.755

SJR Impact

3.215

Publication date

01/01/2011

ISI

000294936600009

Scopus Id

2-s2.0-80051795161

Abstract

Thermal treatment of supersaturated Ti1-xAl xN films (x ˜ 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. © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Keywords

Absorption spectra; Aluminum nitride; III-V semiconductors; Nanocrystalline materials; Nanocrystals; Nitrogen; Phase transitions; Superconducting materials; Tin; Titanium nitride; X ray absorption; X ray absorption near edge structure spectroscopy; X ray diffraction; X ray scattering; Annealing temperatures; Decomposition process; First principle calculations; Grazing-incidence X-ray diffraction; Phase transformation process; Resonant inelastic x-ray scattering; TiAlN; X ray absorption near edge structure; Spinodal decomposition

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