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Metastable phase formation of Pt-X (X = Ir, Au) thin films
The dependence of phase formation and mechanical properties on the chemical composition has been investigated for Pt-Ir and Pt-Au combinatorial thin films. The formation of a single, metastable Pt-Ir solid solution has been observed for all experimental compositions and temperatures. Upon Ir additio...
Autores principales: | , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group UK
2018
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6033916/ https://www.ncbi.nlm.nih.gov/pubmed/29977046 http://dx.doi.org/10.1038/s41598-018-28452-4 |
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author | Saksena, Aparna Chien, Yu-Chuan Chang, Keke Kümmerl, Pauline Hans, Marcus Völker, Bernhard Schneider, Jochen M. |
author_facet | Saksena, Aparna Chien, Yu-Chuan Chang, Keke Kümmerl, Pauline Hans, Marcus Völker, Bernhard Schneider, Jochen M. |
author_sort | Saksena, Aparna |
collection | PubMed |
description | The dependence of phase formation and mechanical properties on the chemical composition has been investigated for Pt-Ir and Pt-Au combinatorial thin films. The formation of a single, metastable Pt-Ir solid solution has been observed for all experimental compositions and temperatures. Upon Ir addition to Pt the experimentally determined changes in lattice parameter and Young’s modulus display rule of mixture behavior which is in good agreement with our ab initio data. Whereas, in the Pt-Au system, the single metastable solid solution decomposes into two phases as the growth temperature is raised to ≥600 °C. The lattice parameters in the dual phase region are independent of chemical composition. The substrate temperature and chemical composition dependent phase formation in Pt-Ir and Pt-Au thin films can be rationalized based on CALPHAD (CALculation of PHAse Diagrams) results combined with estimations of the activation energy required for surface diffusion: The metastable phase formation during film growth is caused by kinetic limitations, where Ir atoms (in Pt-Ir) need to overcome an up to factor 6 higher activation energy barrier than Au (in Pt-Au) to enable surface diffusion. |
format | Online Article Text |
id | pubmed-6033916 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
publisher | Nature Publishing Group UK |
record_format | MEDLINE/PubMed |
spelling | pubmed-60339162018-07-12 Metastable phase formation of Pt-X (X = Ir, Au) thin films Saksena, Aparna Chien, Yu-Chuan Chang, Keke Kümmerl, Pauline Hans, Marcus Völker, Bernhard Schneider, Jochen M. Sci Rep Article The dependence of phase formation and mechanical properties on the chemical composition has been investigated for Pt-Ir and Pt-Au combinatorial thin films. The formation of a single, metastable Pt-Ir solid solution has been observed for all experimental compositions and temperatures. Upon Ir addition to Pt the experimentally determined changes in lattice parameter and Young’s modulus display rule of mixture behavior which is in good agreement with our ab initio data. Whereas, in the Pt-Au system, the single metastable solid solution decomposes into two phases as the growth temperature is raised to ≥600 °C. The lattice parameters in the dual phase region are independent of chemical composition. The substrate temperature and chemical composition dependent phase formation in Pt-Ir and Pt-Au thin films can be rationalized based on CALPHAD (CALculation of PHAse Diagrams) results combined with estimations of the activation energy required for surface diffusion: The metastable phase formation during film growth is caused by kinetic limitations, where Ir atoms (in Pt-Ir) need to overcome an up to factor 6 higher activation energy barrier than Au (in Pt-Au) to enable surface diffusion. Nature Publishing Group UK 2018-07-05 /pmc/articles/PMC6033916/ /pubmed/29977046 http://dx.doi.org/10.1038/s41598-018-28452-4 Text en © The Author(s) 2018 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. |
spellingShingle | Article Saksena, Aparna Chien, Yu-Chuan Chang, Keke Kümmerl, Pauline Hans, Marcus Völker, Bernhard Schneider, Jochen M. Metastable phase formation of Pt-X (X = Ir, Au) thin films |
title | Metastable phase formation of Pt-X (X = Ir, Au) thin films |
title_full | Metastable phase formation of Pt-X (X = Ir, Au) thin films |
title_fullStr | Metastable phase formation of Pt-X (X = Ir, Au) thin films |
title_full_unstemmed | Metastable phase formation of Pt-X (X = Ir, Au) thin films |
title_short | Metastable phase formation of Pt-X (X = Ir, Au) thin films |
title_sort | metastable phase formation of pt-x (x = ir, au) thin films |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6033916/ https://www.ncbi.nlm.nih.gov/pubmed/29977046 http://dx.doi.org/10.1038/s41598-018-28452-4 |
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