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Understanding the microstructural evolution and mechanical properties of transparent Al-O-N and Al-Si-O-N films

Optically transparent, colorless Al-O-N and Al-Si-O-N coatings with discretely varied O and Si contents were fabricated by reactive direct current magnetron sputtering (R-DCMS) from elemental Al and Si targets and O(2) and N(2) reactive gases. The Si/Al content was adjusted through the electrical po...

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Autores principales: Fischer, Maria, Trant, Mathis, Thorwarth, Kerstin, Crockett, Rowena, Patscheider, Jörg, Hug, Hans Josef
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Taylor & Francis 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6844387/
https://www.ncbi.nlm.nih.gov/pubmed/31723370
http://dx.doi.org/10.1080/14686996.2019.1666425
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author Fischer, Maria
Trant, Mathis
Thorwarth, Kerstin
Crockett, Rowena
Patscheider, Jörg
Hug, Hans Josef
author_facet Fischer, Maria
Trant, Mathis
Thorwarth, Kerstin
Crockett, Rowena
Patscheider, Jörg
Hug, Hans Josef
author_sort Fischer, Maria
collection PubMed
description Optically transparent, colorless Al-O-N and Al-Si-O-N coatings with discretely varied O and Si contents were fabricated by reactive direct current magnetron sputtering (R-DCMS) from elemental Al and Si targets and O(2) and N(2) reactive gases. The Si/Al content was adjusted through the electrical power on the Si and Al targets, while the O/N content was controlled through the O(2) flow piped to the substrate in addition to the N(2) flow at the targets. The structure and morphology of the coatings were studied by X-ray diffraction (XRD) and transmission electron microscopy (TEM), while the elemental composition was obtained from Rutherford backscattering spectrometry (RBS) and heavy ion elastic recoil detection analysis (ERDA). The chemical states of the elements in the coatings were analyzed by X-ray photoelectron spectroscopy (XPS). Based on analytical results, a model describing the microstructural evolution of the Al-O-N and also previously studied Al-Si-N [1, 2, 3, 4] coatings with O and Si content, respectively, is established. The universality of the microstructural evolution of these coatings with the concentration of the added element is attributed to the extra valence electron (e(–)) that must be incorporated into the AlN wurtzite host lattice. In the case of Al-O-N, this additional valence charge arises from the e (–) acceptor O replacing N in the AlN wurtzite lattice, while the e (–) donor Si substituting Al fulfills that role in the Al-Si-N system. In view of future applications of ternary Al-O-N and quaternary Al-Si-O-N transparent protective coatings, their mechanical properties such as residual stress (σ), hardness (HD) and Young’s modulus (E) were obtained from the curvature of films deposited onto thin substrates and by nanoindentation, respectively. Moderate compressive stress levels between −0.2 and −0.5 GPa, which suppress crack formation and film-substrate delamination, could be obtained together with HD values around 25 GPa.
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spelling pubmed-68443872019-11-13 Understanding the microstructural evolution and mechanical properties of transparent Al-O-N and Al-Si-O-N films Fischer, Maria Trant, Mathis Thorwarth, Kerstin Crockett, Rowena Patscheider, Jörg Hug, Hans Josef Sci Technol Adv Mater Engineering and Structural materials Optically transparent, colorless Al-O-N and Al-Si-O-N coatings with discretely varied O and Si contents were fabricated by reactive direct current magnetron sputtering (R-DCMS) from elemental Al and Si targets and O(2) and N(2) reactive gases. The Si/Al content was adjusted through the electrical power on the Si and Al targets, while the O/N content was controlled through the O(2) flow piped to the substrate in addition to the N(2) flow at the targets. The structure and morphology of the coatings were studied by X-ray diffraction (XRD) and transmission electron microscopy (TEM), while the elemental composition was obtained from Rutherford backscattering spectrometry (RBS) and heavy ion elastic recoil detection analysis (ERDA). The chemical states of the elements in the coatings were analyzed by X-ray photoelectron spectroscopy (XPS). Based on analytical results, a model describing the microstructural evolution of the Al-O-N and also previously studied Al-Si-N [1, 2, 3, 4] coatings with O and Si content, respectively, is established. The universality of the microstructural evolution of these coatings with the concentration of the added element is attributed to the extra valence electron (e(–)) that must be incorporated into the AlN wurtzite host lattice. In the case of Al-O-N, this additional valence charge arises from the e (–) acceptor O replacing N in the AlN wurtzite lattice, while the e (–) donor Si substituting Al fulfills that role in the Al-Si-N system. In view of future applications of ternary Al-O-N and quaternary Al-Si-O-N transparent protective coatings, their mechanical properties such as residual stress (σ), hardness (HD) and Young’s modulus (E) were obtained from the curvature of films deposited onto thin substrates and by nanoindentation, respectively. Moderate compressive stress levels between −0.2 and −0.5 GPa, which suppress crack formation and film-substrate delamination, could be obtained together with HD values around 25 GPa. Taylor & Francis 2019-09-25 /pmc/articles/PMC6844387/ /pubmed/31723370 http://dx.doi.org/10.1080/14686996.2019.1666425 Text en © 2019 The Author(s). Published by National Institute for Materials Science in partnership with Taylor & Francis Group. http://creativecommons.org/licenses/by/4.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Engineering and Structural materials
Fischer, Maria
Trant, Mathis
Thorwarth, Kerstin
Crockett, Rowena
Patscheider, Jörg
Hug, Hans Josef
Understanding the microstructural evolution and mechanical properties of transparent Al-O-N and Al-Si-O-N films
title Understanding the microstructural evolution and mechanical properties of transparent Al-O-N and Al-Si-O-N films
title_full Understanding the microstructural evolution and mechanical properties of transparent Al-O-N and Al-Si-O-N films
title_fullStr Understanding the microstructural evolution and mechanical properties of transparent Al-O-N and Al-Si-O-N films
title_full_unstemmed Understanding the microstructural evolution and mechanical properties of transparent Al-O-N and Al-Si-O-N films
title_short Understanding the microstructural evolution and mechanical properties of transparent Al-O-N and Al-Si-O-N films
title_sort understanding the microstructural evolution and mechanical properties of transparent al-o-n and al-si-o-n films
topic Engineering and Structural materials
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6844387/
https://www.ncbi.nlm.nih.gov/pubmed/31723370
http://dx.doi.org/10.1080/14686996.2019.1666425
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