About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Mechanical Behavior at the Nanoscale VIII
|
| Presentation Title |
Interface-Mediated Deformation Transition and Quantum Confinement Effects in Ta₂O₅/SiO₂ Optical Nanolaminates |
| Author(s) |
Vivek Devulapalli, Manuel Baertschi, Fedor Klimashin, Stephan Waldner, Silvia Schwyn Thoeny, Johann Michler, Xavier Maeder |
| On-Site Speaker (Planned) |
Vivek Devulapalli |
| Abstract Scope |
Amorphous-amorphous nanolaminates (A/ANLs) present promising pathways to overcome the brittleness of monolithic amorphous materials through interface-mediated deformation. This study investigates the mechanical behavior of Ta₂O₅/SiO₂ quantum nanolaminates with bilayer thicknesses ranging from 1 to 167 nm using nanoindentation and electron microscopy. Contrary to conventional Hall-Petch strengthening, our oxide nanolaminates exhibit inverse strengthening behavior, with hardness decreasing from 7.7 GPa at 167 nm to 5.5 GPa at 1 nm bilayer spacing. Post-indentation microstructural analysis reveals a fundamental transition in deformation mechanisms. While monolithic SiO₂ fails catastrophically via single shear band propagation extending into the substrate, multilayer systems demonstrate shear band multiplication and interface-mediated deflection. At the finest bilayer spacing (2 nm), numerous closely spaced shear bands form throughout the deformed region, effectively distributing strain and preventing localized failure. These findings elucidate the critical role of interface density in governing deformation transitions from localized to quasi-homogeneous modes in oxide A/ANLs. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Characterization, Thin Films and Interfaces, Mechanical Properties |