Nano-Scale Residual Stress Profiling in Thin Multilayer Films with Non-Equibiaxial Stress State
Silver-based low-emissivity (low-E) coatings are applied on architectural glazing to cost-effectively reduce heat losses, as they generally consist of dielectric/Ag/dielectric multilayer stacks, where the thin Ag layer reflects long- wavelength infrared (IR), while the dielectric layers both protect...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-04-01
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| Series: | Nanomaterials |
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| Online Access: | https://www.mdpi.com/2079-4991/10/5/853 |
| _version_ | 1797569309552148480 |
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| author | Marco Sebastiani Edoardo Rossi Muhammad Zeeshan Mughal Alessandro Benedetto Paul Jacquet Enrico Salvati Alexander M. Korsunsky |
| author_facet | Marco Sebastiani Edoardo Rossi Muhammad Zeeshan Mughal Alessandro Benedetto Paul Jacquet Enrico Salvati Alexander M. Korsunsky |
| author_sort | Marco Sebastiani |
| collection | DOAJ |
| description | Silver-based low-emissivity (low-E) coatings are applied on architectural glazing to cost-effectively reduce heat losses, as they generally consist of dielectric/Ag/dielectric multilayer stacks, where the thin Ag layer reflects long- wavelength infrared (IR), while the dielectric layers both protect the Ag and act as an anti-reflective barrier. The architecture of the multilayer stack influences its mechanical properties and it is strongly dependent on the residual stress distribution in the stack. Residual stress evaluation by combining focused ion beam (FIB) milling and digital image correlation (DIC), using the micro-ring core configuration (FIB-DIC), offers micron-scale lateral resolution and provides information about the residual stress variation with depth, i.e., it allows depth profiling for both equibiaxial and non-equibiaxial stress distributions and hence can be effectively used to characterize low-E coatings. In this work, we propose an innovative approach to improve the depth resolution and surface sensitivity for residual stress depth profiling in the case of ultra-thin as-deposited and post-deposition annealed Si<sub>3</sub>N<sub>4</sub>/Ag/ZnO low-E coatings, by considering different fractions of area for DIC strain analysis and accordingly developing a unique influence function to maintain the sensitivity of the technique at is maximum during the calculation. Residual stress measurements performed using this novel FIB-DIC approach revealed that the individual Si<sub>3</sub>N<sub>4</sub>/ZnO layers in the multilayer stack are under different amounts of compressive stresses. The magnitude and orientation of these stresses changes significantly after heat treatment and provides a clear explanation for the observed differences in terms of scratch critical load. The results show that the proposed FIB-DIC combined-areas approach is a unique method for accurately probing non-equibiaxial residual stresses with nano-scale resolution in thin films, including multilayers. |
| first_indexed | 2024-03-10T20:10:10Z |
| format | Article |
| id | doaj.art-1384705125484bd4a1a1adfc73e43e63 |
| institution | Directory Open Access Journal |
| issn | 2079-4991 |
| language | English |
| last_indexed | 2024-03-10T20:10:10Z |
| publishDate | 2020-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Nanomaterials |
| spelling | doaj.art-1384705125484bd4a1a1adfc73e43e632023-11-19T22:58:20ZengMDPI AGNanomaterials2079-49912020-04-0110585310.3390/nano10050853Nano-Scale Residual Stress Profiling in Thin Multilayer Films with Non-Equibiaxial Stress StateMarco Sebastiani0Edoardo Rossi1Muhammad Zeeshan Mughal2Alessandro Benedetto3Paul Jacquet4Enrico Salvati5Alexander M. Korsunsky6Engineering Department, Università degli studi Roma Tre, via della Vasca Navale 79, 00146 Rome, ItalyEngineering Department, Università degli studi Roma Tre, via della Vasca Navale 79, 00146 Rome, ItalyEngineering Department, Università degli studi Roma Tre, via della Vasca Navale 79, 00146 Rome, ItalySaint-Gobain Research Paris, 39 Quai Lucien Lefranc, 93303 Aubervilliers Cedex, FranceSaint-Gobain Research Paris, 39 Quai Lucien Lefranc, 93303 Aubervilliers Cedex, FrancePolytechnic Department of Engineering and Architecture (DPIA), University of Udine, Via delle Scienze 208, 33100 Udine, ItalyMulti-Beam Laboratory for Engineering Microscopy (MBLEM), Department of Engineering Science, Parks Road, Oxford OX1 3PJ, UKSilver-based low-emissivity (low-E) coatings are applied on architectural glazing to cost-effectively reduce heat losses, as they generally consist of dielectric/Ag/dielectric multilayer stacks, where the thin Ag layer reflects long- wavelength infrared (IR), while the dielectric layers both protect the Ag and act as an anti-reflective barrier. The architecture of the multilayer stack influences its mechanical properties and it is strongly dependent on the residual stress distribution in the stack. Residual stress evaluation by combining focused ion beam (FIB) milling and digital image correlation (DIC), using the micro-ring core configuration (FIB-DIC), offers micron-scale lateral resolution and provides information about the residual stress variation with depth, i.e., it allows depth profiling for both equibiaxial and non-equibiaxial stress distributions and hence can be effectively used to characterize low-E coatings. In this work, we propose an innovative approach to improve the depth resolution and surface sensitivity for residual stress depth profiling in the case of ultra-thin as-deposited and post-deposition annealed Si<sub>3</sub>N<sub>4</sub>/Ag/ZnO low-E coatings, by considering different fractions of area for DIC strain analysis and accordingly developing a unique influence function to maintain the sensitivity of the technique at is maximum during the calculation. Residual stress measurements performed using this novel FIB-DIC approach revealed that the individual Si<sub>3</sub>N<sub>4</sub>/ZnO layers in the multilayer stack are under different amounts of compressive stresses. The magnitude and orientation of these stresses changes significantly after heat treatment and provides a clear explanation for the observed differences in terms of scratch critical load. The results show that the proposed FIB-DIC combined-areas approach is a unique method for accurately probing non-equibiaxial residual stresses with nano-scale resolution in thin films, including multilayers.https://www.mdpi.com/2079-4991/10/5/853FIB-DICring-corelow emissivity coatingsresidual stressprofilingnon-equibiaxial stress |
| spellingShingle | Marco Sebastiani Edoardo Rossi Muhammad Zeeshan Mughal Alessandro Benedetto Paul Jacquet Enrico Salvati Alexander M. Korsunsky Nano-Scale Residual Stress Profiling in Thin Multilayer Films with Non-Equibiaxial Stress State Nanomaterials FIB-DIC ring-core low emissivity coatings residual stress profiling non-equibiaxial stress |
| title | Nano-Scale Residual Stress Profiling in Thin Multilayer Films with Non-Equibiaxial Stress State |
| title_full | Nano-Scale Residual Stress Profiling in Thin Multilayer Films with Non-Equibiaxial Stress State |
| title_fullStr | Nano-Scale Residual Stress Profiling in Thin Multilayer Films with Non-Equibiaxial Stress State |
| title_full_unstemmed | Nano-Scale Residual Stress Profiling in Thin Multilayer Films with Non-Equibiaxial Stress State |
| title_short | Nano-Scale Residual Stress Profiling in Thin Multilayer Films with Non-Equibiaxial Stress State |
| title_sort | nano scale residual stress profiling in thin multilayer films with non equibiaxial stress state |
| topic | FIB-DIC ring-core low emissivity coatings residual stress profiling non-equibiaxial stress |
| url | https://www.mdpi.com/2079-4991/10/5/853 |
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