Optical reflectivity and hardness improvement of hafnium nitride films via tantalum alloying
It is found that incorporation of tantalum in a hafnium nitride film induces a tunable optical reflectivity and improves the hardness. The underlying mechanism can be illustrated by a combination of experiments and first-principles calculations. It is shown that the evolution of optical reflectivity...
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Format: | Journal Article |
Language: | English |
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2017
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Online Access: | https://hdl.handle.net/10356/83578 http://hdl.handle.net/10220/42668 |
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author | Gu, Zhiqing Huang, Haihua Zhang, Sam Wang, Xiaoyi Gao, Jing Zhao, Lei Zheng, Weitao Hu, Chaoquan |
author2 | School of Mechanical and Aerospace Engineering |
author_facet | School of Mechanical and Aerospace Engineering Gu, Zhiqing Huang, Haihua Zhang, Sam Wang, Xiaoyi Gao, Jing Zhao, Lei Zheng, Weitao Hu, Chaoquan |
author_sort | Gu, Zhiqing |
collection | NTU |
description | It is found that incorporation of tantalum in a hafnium nitride film induces a tunable optical reflectivity and improves the hardness. The underlying mechanism can be illustrated by a combination of experiments and first-principles calculations. It is shown that the evolution of optical reflectivity and the increase in hardness arise from the formation of Hf1−xTaxN solid solutions and the resulting changes in the electronic structure. The increase in infrared reflectance originates from the increase in concentration of free electrons (n) because Ta (d3s2) has one more valence electron than Hf (d2s2). The sharp blue-shift in cutoff wavelength is attributed to the increase in n and the appearance of t2g → eg interband absorption. These results suggest that alloying of a second transition metal renders an effective avenue to improve simultaneously the optical and mechanical properties of transition metal nitride films. This opens up a door in preparing high-reflectance yet hard films. |
first_indexed | 2024-10-01T06:17:13Z |
format | Journal Article |
id | ntu-10356/83578 |
institution | Nanyang Technological University |
language | English |
last_indexed | 2024-10-01T06:17:13Z |
publishDate | 2017 |
record_format | dspace |
spelling | ntu-10356/835782023-03-04T17:14:40Z Optical reflectivity and hardness improvement of hafnium nitride films via tantalum alloying Gu, Zhiqing Huang, Haihua Zhang, Sam Wang, Xiaoyi Gao, Jing Zhao, Lei Zheng, Weitao Hu, Chaoquan School of Mechanical and Aerospace Engineering Tantalum Reflectivity It is found that incorporation of tantalum in a hafnium nitride film induces a tunable optical reflectivity and improves the hardness. The underlying mechanism can be illustrated by a combination of experiments and first-principles calculations. It is shown that the evolution of optical reflectivity and the increase in hardness arise from the formation of Hf1−xTaxN solid solutions and the resulting changes in the electronic structure. The increase in infrared reflectance originates from the increase in concentration of free electrons (n) because Ta (d3s2) has one more valence electron than Hf (d2s2). The sharp blue-shift in cutoff wavelength is attributed to the increase in n and the appearance of t2g → eg interband absorption. These results suggest that alloying of a second transition metal renders an effective avenue to improve simultaneously the optical and mechanical properties of transition metal nitride films. This opens up a door in preparing high-reflectance yet hard films. Published version 2017-06-13T05:15:02Z 2019-12-06T15:26:00Z 2017-06-13T05:15:02Z 2019-12-06T15:26:00Z 2016 Journal Article Gu, Z., Huang, H., Zhang, S., Wang, X., Gao, J., Zhao, L., et al. (2016). Optical reflectivity and hardness improvement of hafnium nitride films via tantalum alloying. Applied Physics Letters, 109(23), 232102-. 0003-6951 https://hdl.handle.net/10356/83578 http://hdl.handle.net/10220/42668 10.1063/1.4971356 en Applied Physics Letters © 2016 American Institute of Physics (AIP). This paper was published in Applied Physics Letters and is made available as an electronic reprint (preprint) with permission of American Institute of Physics (AIP). The published version is available at: [http://dx.doi.org/10.1063/1.4971356]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law. 5 p. application/pdf |
spellingShingle | Tantalum Reflectivity Gu, Zhiqing Huang, Haihua Zhang, Sam Wang, Xiaoyi Gao, Jing Zhao, Lei Zheng, Weitao Hu, Chaoquan Optical reflectivity and hardness improvement of hafnium nitride films via tantalum alloying |
title | Optical reflectivity and hardness improvement of hafnium nitride films via tantalum alloying |
title_full | Optical reflectivity and hardness improvement of hafnium nitride films via tantalum alloying |
title_fullStr | Optical reflectivity and hardness improvement of hafnium nitride films via tantalum alloying |
title_full_unstemmed | Optical reflectivity and hardness improvement of hafnium nitride films via tantalum alloying |
title_short | Optical reflectivity and hardness improvement of hafnium nitride films via tantalum alloying |
title_sort | optical reflectivity and hardness improvement of hafnium nitride films via tantalum alloying |
topic | Tantalum Reflectivity |
url | https://hdl.handle.net/10356/83578 http://hdl.handle.net/10220/42668 |
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