About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
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Symposium
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Deformation Mechanisms, Microstructure Evolution, and Mechanical Properties of Nanoscale Materials
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Presentation Title |
Exploring Defect Behavior and Size Effects in Micron-scale Germanium from Cryogenic to Elevated Temperatures |
Author(s) |
Ming Chen, Alla S. Sologubenko, Jeffrey M. Wheeler |
On-Site Speaker (Planned) |
Ming Chen |
Abstract Scope |
Micron-sized single crystalline Germanium displays enhanced carrier mobility under mechanical straining, which makes it a key material for optoelectronics and ultrafast semiconductor devices. However, the extreme brittleness of Ge constrains its processing and applicability especially at low temperatures. In this study, we demonstrate Ge is plastically deformed even at cryogenic temperatures by using in situ compression of micropillars. Micromechanical tests were performed at temperatures from −100 to 400 °C (0.14 − 0.56 Tm). This wide temperature range includes two transitions in dislocation-mediated plasticity: shuffle-to-glide (~0.31 Tm) and brittle-to-ductile (~0.47 Tm). Dynamic mechanical tests were performed to measure activation parameters for each deformation mechanism. The size effect in defect-scarce Ge was observed to be weak for deformation via partial dislocations but more pronounced via perfect dislocations. This study provides in-depth information and comprehensive knowledge for the defect-mediated plasticity in tetravalent semiconductors and practical guidelines for fabrication of robust Ge-based micro-structures. |
Proceedings Inclusion? |
Planned: |
Keywords |
Characterization, Mechanical Properties, Other |